I've installed 13.0 RC2 on a thinkpad T61 with middleton bios, 8GB ram and 256GB
ssd this evening, to give it a try.
So far everything is working well. Wifi works, and the lagg driver works to provide auto-failover between wired ethernet and the wifi adapter. The x11 server has selected the glamor driver, performance seems good. Suspend works (including on lid close); resume is a little slow (as it was on 12.x) but it works. I've installed zfs, performance seems to be as good as ufs.
The whole system feels nice and snappy in use, although I am using a fairly thin gui, namely windowmaker. Firefox and chrome are both working, video playback in chrome works. It seems stable, I'm not seeing many error messages in dmesg or /var/log/messages. So far, so good.
I may try the kde5 meta package later.
I would encourage anyone interested to give it a try, it seems pretty good. There is a a nice uptick in performance compared to 12.2.