Yamaha DTXpress/DTXplorer/DTXtreme

hello everybody, i'm a student in the UK who is seriously considering 
purchasing a dtxpress kit as soon as i can get the cash together. 
i'd just like to ask all u guys, as u know what we're talking about 
here, about the kit before i fork out the cash.

firstly, from what i understand its a very good buy but has some 
problems when trying to listen with headphones, is that the case? and 
has anyone found a way around this? i know very little about 
recordiing but will definately want 2 use it 2 record and will 
without a doubt hook it up to my pc. is this a difficult thing 2 do? 
what format are recorded tracks in?  i would also like to use 
recorded tracks with some of my frinds recordings of other 
instruments, to create a few simple demos for us to listen to. is 
this possible?  how strong is the kit, the physical aspect of it i 
mean. does it seem strong & lasting or do u need to keep replacing 
parts that break?  finally (b4 i think of another 3000 questions) i 
play with a fairly large kit - with 3 crashes, 3 rides, a number of 
splashes and usually (if possible) a 7-piece kit with double base. 
now obviously i understand that this is not possible to emulate with 
the dtxpress, but how expandable is the kit?  how far can i expand 
it, even if it costs a little extra, is there anything that might 
allow me to exceed its original expandibility. (if there is such a 
word)

i'm sorry if i sound alittle ignorant but this really is a completely 
new thing for me!!! all i know is that i have been heavily advised on 
purchasing this kit and am trying to understand as much as i can 
about it b4 i do.

thanks alot for your help
pete