I run MorphOS 2.2 on my Efika and it works fine. With 2.1 I sometimes had some weird behaviour, but with 2.2 I haven't experienced any bad behaviours yet.
E.g. tonight I had the Efika powered up to listen to some music, watch a youtube vid, browse the net with AWeb and Sputnik, check my mails with SimpleMail and play WipeOut 2097 for a quarter of an hour and to lurk around on #morphos with WookieChat. Uptime w/o a reboot was >4 hrs, then I decided to switch off the device because I moved over to my bedroom (where my netbook is handier than the Efika and I had to run a serious word processor because I had work for a couple of hrs b4 going to sleep now).
On my Efika usb works quite reliable, but others seem to have less luck in that regard.
The Efika is a nice system to play around with, but still I prefer my Pegasos over Efika.