I would not reccomend using keyboard drums in the studio with the exception of maybe a PLG percussion card on a Yamaha, but even still. Actually what it really depends on is the program material being recorded.
Personally, I do drum tracks first, always.
How "alive" your drums are has a direct effect how the material is interpreted and noticed. I even master drum tracks separately from the rest of the material and then add them to the final mastering.
Back on the topic (sorry bout that), maybe you should get a demo of a Roland MC-909 or MV-8000. The MV is much cleaner than the MC. I like the MV, but it costs a lot more too.
_________________________
MORPH! Sound