I preferred the linearity of Partners in Time. In fact I thought the game pointed out what has been wrong with Nintendo games for the past five years: Partners in Time was rushed, definitely, it has shortcomings. In spite of that, I thought the gameplay was 100% good game, where other Nintendo games in the same situation just pumped themselves up with boring extras. Go back and collect a zillion thingees to get 100% (Super Mario Sunshine) or travel back and forth across this map four times in order to get to the boss (Paper Mario: TTYD).
Granted, the downside is that the game is a little too empty...there's basically nothing outside of the main adventure except for bean collecting, and the main adventure seems to stop short of what the first game accomplished. However, I liked how it didn't try to extend itself with collectables and how I didn't have to battle through tons of obstacles and monsters to get to my final destinations on the world map.
As for the hype for Contact, that's the thing with previews: they're usually positive, you don't find out about game flaws until the reviews come out. So I got hyped up for it because it was looking cool, and yes there weren't a ton of great RPGs up until now. Whether or not you consider Mario & Luigi: PiT good, it's still just one game.