I found Partners in time to be the weakest of the mario and luigi series so far. its still a fun game and there are some nice references in BIS to PiT but if your not enjoying it then I'd say drop it and play BIS.
The game wasn't memorable enough for me to say. The bosses were meh, the landscapes were meh, enemies were meh, final boss was meh, battle music was meh, bros items were meh. The whole game was pretty bland.
Bowser's Inside Story was great though, it was different, but still had charm like the original.
Haven't played Dream Team, the demo didn't convince me.