Yamaha DTXpress/DTXplorer/DTXtreme

Hi,

Is anyone able to explain the differences between the DTXpress and 
DTX 2.0?
I would like to know as many differences as possible as i'm soon to 
buy one of the kits and want to get the best out of the two.

Some would say the DTX 2.0 is but what about the DTX 2.0 not having 
the PC-host facility ?  Is it really important to have this? I'm not 
even that sure what i'd use the PC-host facility for.

Also are there any other things that the DTXpress has that the DTX 
2.0 does not have?

Any help from anyone would be apprechiated,

Cheers,
Neil