Compared to a good real drummer who might subtly slow down/speed up during the course of a song, etc., ALL of the midi solutions based on snippets or loops will sound inferior. But some seeem to sound more stiff than others.
I ask because, acknowledging this limitation, IMHO, Drumtrax sounds like one of the more realistic.
That is subjective, of course, but an objective measure is to examine the midi data. For some products, you will find kick, snare, etc. hits quantized exactly on the grid, eg. snare on position 1.2.1.1. Others allow the drummers' imperfections in timing to remain, e.g. 1.2.1.7 (7 ticks deviation).