I've been waiting for an easy to use free VSTi for drum sounds ever since I bought Cubasis last year. Before I'd either been using GM sounds or loops created using HammerHead.
This is a great piece of freeware courtesy of Muon and those ever lovely guys at CM.
I don't bother using the supplied kits. I just import my own drum samples (usually TR-909 and Yamaha RY-8) and adjust to my tastes. I've found that many of the supplied kits need to be remapped for me to use them effectively so I generally don't bother as it's too much like hard work. What I would like to see is some sort of "Pad # to Midi Note" which would remove a lot of the guess work although I'll probably write that myself and post it somewhere.
The filter is pretty good, especially as you can apply it globally or to specific samples. My personal favourite is the bitcrusher. When combined with the filter you can create some really crusty loops.
It's a shame CM and Muon couldn't make SR-202 and CM-101 available as a download over the net. I'm sure nobody would quibble about paying a very small amount of money for the priviledge.