All you get from having a save are a few pieces of gear. Nothing that's really worth it.
If you want to search for collectibles and do the (somewhat meager number of) side quests, you can do that on a second playthrough. I don't think it has much replayability, at least not much more than the first game.
I feel that with Rock Band Blitz, songs you enjoy listening to are more important, since the gameplay is a tad bit less involved. I usually pick songs to play that I want to hear at that moment.
I do like songs with good drum parts. As someone who kinda sucks at the drums on normal Rock Band, it can be really fun to pound out some satisfying drum fills on the controller. Rush, Boston, and Foo Fighters all have some interesting drum parts.
I'll play it. From the way it's looking to turn out, I will probably wait a long while, though. I haven't actually played it myself but the Quick Look made it look absolutely terrible and I don't have much faith.
The DualShock 3 definitely felt like a step backwards for Sony. The sticks have always felt a little strange to me and I, like most people, hate that there are no trigger guards on the back. It's a perfectly serviceable controller, though. Could be far worse.
The 360 controller, however, is the best controller ever made.
Not at all interested in Armored Kill. As crazy as it sounds, this is not what I want out of Battlefield. I like the smaller maps, with a focus on infantry combat and maybe one or two vehicles. I can't even remember the last time I played a map like Operation Firestorm or Caspian Border.