I played with this build, but it lasted less than a day. The browser seems to be a downgrade from 4.6. It's slower and buggier, but that may be because it's the media net browser rather than internet browser. Google Talk didn't work, and neither did Facebook 1.5.

The really annoying thing is that all drop down lists in the UI are borked. The DDL's now show with a frame around them, so any page using a DDL element has some really messed up looking formatting.

Using DM 5.0, the downgrade could only be accomplished with network access interrupted. DM kept wanting to push me to AT&T's approved firmware, rather than my locally-installed 4.6.0.266.