It has been a while since I got the boards and at the time I left some thoughts on the project page. I really like its simplicity which made assembly very easy. To develop on such a board I'd prefer an onboard serial converter just to eliminate having to chain several gadgets together but I have some use cases for the boards nonetheless:
I've added 2mm headers to the ESP-12E footprint such that I can just plug in an ESP-12E or an ESP-01. I use this board to test new ESP modules to make sure they work after their month-long trip.
I haven't implemented the second use case yet but I plan on making the other one into a wireless serial bridge using the ESP-Link firmware and a virtual serial port tunnel to make it compatible with just about every program/tool out there. The reason for this is that I do most work on my laptop when it's actually on my lap and this way I won't have to worry about the USB cable pulling the devboard and breadboard off my desk.
And finally here are some mods that I made for/to the board:
Simple adapter board to connect power rails. This was more feasible than using those female headers with long pins and plugging it into the top.
I used angled headers for the serial header and the Vusb/Vin pin. The idea was to make it possible to plug it directly into the serial converter (or some in-between adapter board) and have them not be perpendicular to each other. Also added some rubber feet for good measure.