I use
Session Drummer 2 in Cakewalk's Sonar Producer Edition, and combined with a set of midi drum loops from SmartLoops and PGMusic's Band in a Box, I've been able to get some excellent results and "real" sounding/feeling drums. Also, I've been able to convert stereo drum recordings into midi....edit them, and spit them out with new tones via Session Drummer....although this takes a quite a bit of effort....but can save you the production cost of recording real drums in a big studio.
A buddy of mine has his drummer record midi tracks via V-Drums and then he imports them into Session Drummer....with excellent "real" sounding results. You can even hire pros online to put down V-Drum tracks for you.
I have used older versions of Reason in the past, and what I don't like about it is that you generally are using outside of your DAW (Digital Audio Workstation....ProTools, Sonar, etc.). I like to see ALL events in one time line.