Well, I've used EZ Drummer, DKFH, SD2.0, Music City, Slate, and know my way around blending other samples together, basic compression, eq, etc.
I guess my question was more geared not really at the ease-of-use, but more for the quality of the samples compared to each other. From what I've heard, Metal Machine sounds pretty damn good. And it would save me $20 too. lol. I just wasn't sure if I should pass up MF for only $99, and unfortunately I can't afford both at the moment.
Edit: after doing more reading it looks like a lot of you prefer the samples in Metal Machine compared to MF. Hmmm...