Im running it now, I have it on a WRT350n,WR850 (Surfboard), and WRT54Gv1 all running different versions.
I would wait until v24 final is out in a month or two before jumping to the new FW, the v23 sp3 is pretty decent for standard WRT routers. The release canadates have some issues and I have a strong fear of bricking my 350n. Also check out the optiware packages, you can do some cool stuff with it, I'm doing some pretty cool things with my router (Bittorrent, VPN,HTTP/FTP download queue to NAS, etc(.