Yamaha DTXpress/DTXplorer/DTXtreme

> Has anyone compared these?  The pads look a bit nicer, but the module 
> doesn't seem to be as nice (not nearly as many drum kits, no audio 
> input)

I can't comment on the pads but I just upgraded to a DTXpress module  from a Alesis D4 and did own the DM-5 for about 4 months.  You 
are correct in assuming the modules are drastically different. You will have quadruple the fun with the Xpress's sequencer, songs , click 
track  and editing capabilities. 
One thing I would like to add to Ed's excellent comparison is the very limited 'tunig function' on the DM-5.  It's only up 3 semi tones  and 4 
semitones down.  For instance you can't get the Gong sound by bringing the cymbal pitch down 2 octaves. 
Also you won't find a user group for the DM-5 as informative as this DTXpress group.  Which is something  to  consider  if you are new to 
edrums. 

Jun