Update:
The screens are really sharp and clear. IMO the best screens on Spring and LOT better than the EVO. Go into the store and compare a photograph, you will notice the difference.
Speakers are crisp and clean. They aren't as loud as the Motorola phones but are cleaner sound.
The tablet extension app makes most apps work in dual screen mode but a few of em don't run well. The biggest benefit of the dual screen though is when watching video or browsing on the web because it's basically a tablet.