For our Jazz Drums Collection, we actually recorded up to 7 velocities (pp, p, mp, mf, f, ff, always adding occasional ppp or fff where it seemed appropriate to provide a more in-depth rendering of eventual sonic and accoustic varieties) for each hit-type, along with multiple alternations, playing positions and (mostly speed-controlled) repetitions.
This approach - i.e. paying closer attention to a serious variety of articulations, while still capturing the individual dynamic range of a specific drum or cymbal, as opposed to stubbornly record and map even all 127 possible velocity layers for only very few single hits - turned out to better complement the way we personnally prefer to work when creating sample-based drum tracks, especially for Jazz music.
By the way, our new Jazz Drums Tutorial Video and a couple of Demo MIDI files are already available for download...
Cheers and keep swinging,
Mrx