I have a copy of DKFH as well as FruityLoops...I have to say that the acoustic drums samples offered by DKFH are quite a bit more believable than FL. But putting them together to sound like a real player is where the work begins. To get the most out of all the tuneable features, takes some doing and this aspect of the appliction isn't for beginners...the learning curve can be steep. Don't get me wrong, you can load this thing up, get your midi controller out and start bangin' out the beats quite quickly but the get the finess and detail which gets people thinking that you've got a live drummer on board will take some work.
I think it's a great product if you're committed to electronic or midi drum sources and cannot get a real drummer on board. I simply dabbled in the midi stuff so I never got to be real comfortable with either application. I'm lucky that we've got drums and a resident drummer here.
I think DKFH has a website where you can hear and download some of their product. Check around.