The Dune miniseries is about 4,5 hours long. If the second Dune movie will have a similar length to the first one, the pair is going to be more than 5 hours long in total. So the movies wouldn't have to be more compressed. That surprised me a little.
Unfortunately the SyFy adaptation reeked of cheapness to me. Plot-wise better than Lynch's movie, but aesthetically terrible, and with some pretty bad acting too.
Eh, yes and no. A lot of the outdoor scenes and effects look pretty poor, presumably due to TV-level funding, but the interior set design and costume design are excellent IMHO. Also, the only bad actor was the one playing Paul; I thought everyone else was fine.