Yamaha DTXpress/DTXplorer/DTXtreme

Hi, this is my first post...pls be gentle to me :)

I have an opportunity to purchase a few years old original DTXpress ver 
1, or a few months old DTXplorer, both is about the same price.

I couldn't find the specs for the DTXpress I, I'm not sure if this is 
really much better than the more recent DTXplorer. Please advise.

thanks,
Arief

PS: I'll be hooking up the kit to my PC via Roland's MIDI to USB 
converter to play DTXMania/Drummania simulator.