http://www.mag2.cjb.net currently has a partial planeshift spoiler! Based on a preliminary glance, it looks like planesshift might be better than Invasion...
More often than not, if history is the judge, then the sequel IS better than the original. My opinion of course. Alliances was better than Ice Age. Visions was better than Mirage. Nemesis was better than Masques. There are exceptions: Saga is still SAGA. But in general, the follow-up to a main set is supposed to be good.
My wild guess is that the sequels HAVE to get better.
The Big Expansion get bought because of the new card pool that will be needed, with the mechanics etc ...
If all the good cards are in the big set, then no need to buy the small expansion 1.
Repeat for small expansion 2 of the block wich will need real "power cards" to have people by them, as they already got the big expansion and the small expansion 1.
