Yamagi is currently being updated and new versions released periodically. I am certain it is the most worked on client currently.
P.S. I tried out Yamagi, and immediately got the old classic "Cbuf_AddText: overflow" error (autoexec.cfg > 8 kbytes). Yamagi seems to be missing a few quality-of-life improvements that have been added to r1q2 and q2pro over the years. Always tradeoffs of one sort or another I guess.
Yamagi never interested me. Doesn't seem to be an improvement and from what I gather people use it for convenience rather than quality.