Back in 1983, we in a small Estonian town Tartu (this time behind the Iron Curtain, of course) built a 8-bit PC, based on 8080 (or, to be precise, it's illegal Soviet clone K580VM80). It was a great time...
Thus, when I found the RC2014 on Internet, I got excited. Yes, we have many emulators running on PCs, Macs, Pis -- but they are not the right thing.
And I, a former programmer, am a bit scared about the thought building all the hardware...
However, I know from which end to grasp the soldering iron...
So I read the descriptions of the RC2014 versions, and decided to order the "Full Monty". Why?
Because it runs CP/M. This was _the_ operating system of the early eighties, and it can do almost everything.
....
In addition to the RC2014 Pro kit I ordered the "Raspberry Pi terminal" because this lets run the RC2014 without PC.

Enter Mr Spencer Owen, the "Mr RC2014".
He posted the package almost immediately, and it arrived quickly. Very well packed, all parts present and intact.
However, I would recommend to have a multimeter or, better, some Chinese component-multitester, at hand. Then you can be sure you'll solder all resistors and capacitors in right places.
I also think that the soldering equipment must be a bit better than entry level. I have a soldering station with temperature control, and the iron has some medium-size tip. As all pads are at least 0.1" apart, this is sufficient. In a other review a 0.7 mm solder s recommended. My shop hadn't this at the moment, so I got 0.5 mm one, and it worked very well. Maybe the soldering time is a bit longer than with 0.7, but I can control the process better.
For old people like me, the headset with magnifying glasses (something like https://www.oomipood.ee/product/vtmg13_suurendusprillid_led_lambiga_1_5_10dioptriat_1_375_2_5x) is recommended although not absolutely necessary.
I started at the backplane. Not liking the idea have "regular" and "enhanced" slots on it, I bought additional 1x20 sockets and made all slots enhanced. This means 720 solder pads for slots only, so it's no wonder it took me three evenings to sold all things together.
There's a recommendation on 'net how to hold the slots in vertical position while soldering: https://groups.google.com/forum/#!topic/rc2014-z80/pA9cCaR9568 , but there's a small problem: just _every other_ slot matches with the connector's pins. So I soldered first every other slot. Then I sacrificed two connectors (of my own spares), cutting two pins where the "wrong parity" slots would be, and using them, soldered the remaining slots.
The backplane soldered, I connected the power and threw the switch. And the green light was given :)
Then I soldered all modules. When next one was ready, I inserted it into backplane and made sure the green LED still lit up. (Didn't insert any IC-s yet).
All modules ready, I inserted the IC-s, put modules onto backplane and threw the power switch.
The "Pi terminal" started to work, but the Z80 machine didn't.
Mr Spencer reacted promptly on my complaints. It turned out that I had soldered the "regular" pins on the RAM module, but there should be 2-row "enhanced" connector. Luckily, as Mr Spencer indicated, there's only one pin in use from enhanced row, so the error was corrected with a jumper wire.
Then it turned out that by mistake I had got wrong ROM. Again, Mr Spencer was very helpful and posted the right one at once. So I could 3 days learn the commands of the "Simple Monitor", which was not useless :).
The weakest point of this configuration (Pro kit + Pi terminal) is the software of the Pi terminal. It has poor character quality on screen and is not configurable (screen size, etc.). Unfortunately, the software is not written by Mr Spencer, and the creator seems have lost interest.
This is a point I will investigate... after all, the code (PiGfx) is available, and one Mr Pierot seems having done some improvements...
Meanwhile I decided to continue with PC terminal, and -- as recommended -- the TeraTerm program.
I messed around a whole day, having very erratic connection between RC2014 and PC... until I got another USB-serial converter. Then all started to work.
So when the right ROM arrived, I just had to plug it in, and CP/M was airborne... Great feeling.
There is a lot of CP/M software on the 'net, so the only problem is: how to transfer it on the RC2014?
Fortunately, other people had this problem earlier ;) See Mr Grant Searle's page http://searle.x10host.com/cpm/index.html
And, with the help of the DOWNLOAD program, transfer the XMODEM program as the first thing. (I saw that DOWNLOAD will hang sometimes).
And then... I have been playing with WordStar, MBasic, dBase II, etc., etc. for more than a week. And with Turbo Pascal. Especially with Turbo Pascal. What a fun to write-compile-run...

So, to resume:
1. Superb kit. Very well manufactured, errorless, capable.
2. Very good service (prompt posting, excellent support).
3. Satisfactory documentation. Not for the beginners, but it suited for me who has some bits of information from both hardware and software sides.
4. The best property -- when you have the machine up and running, then the fun does not end, but just begin.
5. The only thing that has to be changed -- the Raspberry Pi terminal software.

Thank, you, Mr Spencer!

Edit on 20200331: I found M. Pierot' software for Pi terminal at
https://github.com/fbergama/pigfx/blob/master/bin/kernel.img
It is considerably better, especially the 8*16 font. The downside is that it is not exactly VT100 nor exactly ANSI, so one has to readjust Turbo Pascal, WordStar, dBase etc. Taht is not a great problem, but the ESC sequences for color controls are veeeeeeeeeeeery long and do not fit into dBase places, for example. Still, you can live with monochrome picture...

I purchased the Full Kit as an addition to an existing RC2014 Pro system that I recently built. The board was packaged well and arrived to the US in a reasonable time. The instructions and documentation were straightforward for assembly. One of the things I do after the soldering is done is to visually inspect each joint closely to make sure it was soldered well. I also clean the flux off the board with a small brush and alcohol. I installed the board in my system and it came up with no problems. It's a great purchase to reduce the board count on your system.

Have yet to assemble the board, but inspecting it was already a pure joy.
Well packaged and orderly grouped. Boards look fab. Instruction is quite detailed and with pictures.

I came rather close to destroying several of the cards which came with the kit because assembly was not obvious to me, and going to the webpages of the vendor was not helpful. Although webpages DID exist, they were not linked to via any of the common landing points to the website. I only found out about them AFTER voicing my concerns on Twitter, and only after receiving a *direct URL* to them. One such example is how to prepare extended bus connectors, which can be found at https://rc2014.co.uk/1426/preparing-enhanced-bus-connectors/ . I wish I'd known this sooner!

Otherwise, the kit as a whole was quick to assemble (assuming you have soldering experience), and after accidentally swapping the RAM and ROM chips on the memory card, I was able to get the computer to boot. It took me about two days of work to get everything together. This product functions exactly as advertised, and it's fun to be able to put something together and see it work. Some of the diagnostics that went into double-checking things were working were part of the puzzle-solving, and was both elucidating as well as exhilarating to see things in the real world behave more or less as they're described in the data sheets. I do recommend you have an oscilloscope (50MHz or greater bandwidth recommended) on hand as you're building the kit, so you can see signal waveforms are behaving as expected. Test early, test often. You'll learn more that way.

I strongly recommend this product. Although it came with no documentation, and there were some places where I had to guess how things were to be put together, I found the vendor to be exceptionally cordial and very helpful. I eagerly look forward to contributing my own 3rd-party modules for this ecosystem.

Just powered up my retro RC2014 computer - Worked just perfectly first time. Very happy. Easy to build, took my time to double/tripple check as i go.

If you want to build a computer, a Retro Computer - i can highly recommend this.

Package arrived in Australia, just fine and quite quickly too - just watch out, as Australia Post does not integrate with Royal Mail - so the tracking system's last entry will be its left the UK. Then a few days later its at your front door!