One thing though, I think the uBitX is a ready assembled board so it's not so much a build as an assembly isn't it?
Interesting point. Yes, the board is already populated and ready to go. Yet there is no enclosure, no power supply, and most importantly, no antenna. I'm thinking of this project in terms of a "build" because there are a great number of permutations it could still undergo considering how tweakable it looks, not to mention the options for adding on. I've seen people do some impressively different things with this design already. Sure, I could buy a box and a battery pack and an antenna and use the software in its stock form... but where's the fun in that? I might as well buy an SK's whole Kenwood rig and spend an evening scraping his call off of all the surfaces. I'd rather try to make something my own, even if I'm not quite at a point where I can improve on the fundamental design.
I have the BITX 40 and uBITX, they are both really fine QRP transceivers. In fact these are my only two pieces of gear right now, I sold my old Yeasu after I purchased the BITX 40 and haven't looked back. As others have stated, SSB voice at QRP power levels can be a challenge at this stage of the solar cycle. If you know CW or are into digital modes, then you will have no problem working the world. If SSB voice is you thing then you might want to consider buying or building an external PA, however I've been quite happy at QRP power levels and have had no lack of success with both voice and digital modes.
The design of the transceivers are really easy to understand and infinitely hackable/modable. One of the best features is the large and very active community of users/hackers/moders at https://groups.io/g/BITX20
I gave the BITX40 a look, but I decided to go with this one, (mainly because I'm interested in 80 meters and I like having the CW option out of the gate, although from what I've read, it sounds as though the keyer really needs some work).
Thank you all for weighing in. I've always been interested in QRP; it just seems like there's a bit more finesse involved from an operation standpoint, and I have much to learn.