I'll go off-track here and suggest Addictive Drums
. I own SD2 with some kits, and like it plenty, but AD is less money, and surprisingly easy to use, while still sounding great. SPlitting out to separate tracks is much simpler than SD2(can't comment on the Slate stuff as I have not used it). Check out some youtube videos on any that you are curious about. You'll find lots of info and hear most of the options. Personally, If you want to use the midi loops, I think AD has an edge in how you can sort and search.