I've heard reports its a bit 'laggy' but then the first releas always will be
quote from XDA:
Impressions so far:
-ui lags a tad more initially, but on some occasions is faster than mcr2.9
-phone works, calls seem a bit laggy, though that might be due to the network
-android market loads, shows apps and even my downloads, but I can't download anything.
-Google maps/navigation boots, I get directions, but I can't use it because it requires the speech synthesis library from the market.
All in all this is a fun build to play with, but I wouldn't recommend it for a primary phone
I.E wait untill a few more releases but not far away I am sure before we have a nice running 2.0 version Hero!