I bought two of these kit for my daughter and one of her friend, both 9 years old, and they both were successful building this kit. It is almost as simple as it could be, both worked perfectly and they really enjoyed the result. On my side, I find these kits really great, the instruction are nice, the price for complete kits is pretty great, overall I'm really happy. Just one suggestion for the store owner: If you make a new revision of this, could you revise the silkscreen? reading the resistor number is not so easy with the resistor drawing on top of the letter, enlarging the resistor to avoid having the lines over the text would be great.
Got my unit in the mail and it works as described! ATTiny 85's were textbook perfect! ATTiny 84's had a small issue which after emailing support I found there are two Arduino cores you can install on the chips. So once I understood there were two competing cores I was able to make the needed changes and got them up and running easily as well. The ATMega 328p's I had some initial difficulty which I attribute to having a strange bootloader on the chips from where I purchased them, but once I was able to completely reset the chip and upload my own bootloader those work perfectly as well now too!!
It was awesome I was able to take my ATMega 328p's and get them to run on internal 8MHz clock instead of having to wire in a 16MHz crystal to the chip. So I'm completely satisfied with the programmer and it's abilities, and contacting support was easy, fast, and excellent!
I only gave 4 stars on documentation because I think it's needed to post a message in the instructions/documentation about the competing ATTiny 84 cores on Arduino and how depending on which core you use will affect the pin number assignments and could cause the blink code to not work on the programmer thus making a user think something is wrong, when it's just the pin assignments are moved around. :)