Here's my review, followed with some feedback for possible improvements:
HARDWARE: The fit and finish for the assembled board is quite excellent. The silkscreen is reserved for labels that the user needs to know (pinouts, the function of LEDs, etc.) and doesn't show the part designators, which is kind of a nice touch. The solder joints all look textbook (correct amount of solder, good reflow settings, etc.). The micro USB connector also wisely has two tabs that go into the board for mechanical strength and looks like it will be fairly robust.
SOFTWARE/FIRMWARE: I wasn't able to get the stock CANable firmware to work with can-utils on my setup (xubuntu in a virtual machine) despite following the instructions. However, the candleLight firmware worked instantly and it was very simple to flash it following the instructions on the CANable website: https://canable.io/getting-started.html#alt-firmware
FEEDBACK ON POSSIBLE IMPROVEMENTS: SOFTWARE/FIRMWARE: 1) Documented API/drivers for Windows, 2) Windows compatible Python library, 3) support for Busmaster. These would really push this up to be my hands-down go-to CAN-USB adapter. I'm fine with running linux in a VM for myself, but I have a need for a CAN-USB adapter that customers can use to configure devices themselves with a GUI and update device firmware via a CAN bootloader without having to use linux or spend hundreds of dollars on a CAN adapter.
HARDWARE: The only hardware suggestions I have is 1) to include labels for the jumper pins on the bottom side of the board as well as the top that includes some sort of boxing to indicate which jumper position does what (this understandably may be difficult to do given the small size of the board), and 2) mounting hole features like the isolated version has would be nice to have, although it's understandable that they're not included to maximize the number you can get out of the panel.
I have a bunch of other CAN interfaces and all of them are (much) more expensive than the CANable. I usually use a Kvaser Leaf Light HS but it requires a special driver that's a pain to install on a Pi3.
I ordered some of the CANables not expecting much but I'm impressed so far. I especially like the CANtact library for direct Python usage without messing with drivers or the SocketCAN interface.
We developed LabVIEW programs to talk to the CANable board over the VirtualCommPort at 115.2k and it works great. The blue status light blinks every time a CAN message comes in. This thing is compact and fast! techmor.com
I evaluated one of these for use in an industrial control related application. The specific use is for temporary connectivity for testing and setup. Due to this special environment I wrote our own driver interface directly using the text string command set. It worked flawlessly when connected to a known good CAN bus. That was the only issue, "when connected to a known good CAN bus". During test and setup the CAN bus may be down. To solve this problem I have pushed out a firmware update having an added command to get the CAN port bus state so I may discover soon enough that the bus may be down and so force restart CANable. Problem solved. I have sent this update back, Ethan plans to test and incorporate it. I have the update posted on my website, www.electronics-software.com, available for download as well. I also have created some detail documentation of the text string command set and reply content, included in my update. The company I am doing this for plans to deploy in the field service area.
I used 4 of these in a USB hub to record data from my car's 4 CAN buses simultaneously. It works perfectly (it basically shows up as a USB serial port, and then the SLCAN encapsulation on top of that - you can use canutils or just read the ASCII serial output directly depending on what you want to do), and I was able to capture all the data with no dropped packets.