The samples don't sound that bad but the placement of them is pretty bad, especially in the last .mp3 file:
(FullMix, Hard Rock, kick/toms and snare 100% replaced
www.stevenslatedrums.com/demo/stevenslate6.mp3)
They are way off in timing or way too on the grid. I wonder if the samples were cut tight as they are playing a touch late.
Anyway good luck.