i also got LE from my tascam US-122. i wouldn't know how watered down it is because i haven't been able to tool around with other cubase programs, but i've had no problems at all with the software, and i've put countless hours into it.

i had the same problem with finding a good way to make drum tracks. i bought battery 3, but i don't have enough RAM to run the actual program as a VST plugin. it would take forever to load and get all choppy. what i ended up doing was simply using fruity loops as my drum track program, and imported whatever audio files i wanted from battery's library. i know it isn't how the program was meant to be used, but hey...i still have gigs of kickass beats and i've made several (some even quite intricate) drum tracks with this technique.

but maybe i'll look into the ezdrummer thing. seems a bit less painstaking.