Yamaha DTXpress/DTXplorer/DTXtreme

I'm wondering if the new DTXpress3 cymbals can be used without any 
problem on the DTXpress2. Specially the hi-hat en 3 zone cymbal look 
very interesting to me.

I hope the hi-hat sound has improved, I think the ones on the 
DTXpress2 are far too light, any (new) tips on that?

Can anyone tell me how to get a new midi file into the brain? 
Everytime I try this I can load one song and then I get a memory full 
message. I thought I could load 32 songs?

Tom