RockBand Instrument Changes

As far as I can tell the instruments for RockBand Beatles and RockBand 2 are exactly the same. Are there any differences betweent the instruments for RockBand 1 and 2? Seems to me it would make more sense to save money and buy the set for RockBand 1 and then just buy the RockBand beatles game, still saving money in the process.

From what I know, the Rock Band 2 instruments are far superior to the Rock Band 1 instruments. I don't know the specifics, but the drums are much better and so is the guitar.

And are the guitar hero instruments compatable with the rock band games?

And are the guitar hero instruments compatable with the rock band games?

Superman1938