Dell Streak 5" or Dell Streak 7"?

Hello, I have a lot of doubts about tablets. I wanna have one, but is this true that 7-inches tablet have a screen resolution problem and they are worst than 10.1"? Are there any plans for dell to keep upgrading the Streak 7" android? Android 3.0, Will be the next upgrade, or it will never happen?
Anyway, which is better.. dell streak 5 or 7?

Thx, :)