One of my friends that I mix for did a lot of listening to the demos and went with Metal Machine. To make it easier to mix his stuff I went and picked it up on sale and really like it myself.  I have a lot of kits for BFD2 and Superior Drummer that often win out over it, but I've used it for a couple of things and it worked out great.

I just ordered the EZX two pack and got 1) Indie Folk and 2) Metal Machine.  While I looked hard at Rock Solid since it was recommended above and almost grabbed it, I found myself more interested in Metal Machine.  Rock Solid just seemed a little "muddy" to my ears.  Also when I googled Metal Machine to find critical reviews, I was impressed with how well Metal Machine was received by the metal community itself.  It was overwhelmingly recommend over DkFH and was praised at how well the samples sounded out of the box.  It will add to my EZX libraries and as I mentioned previously, it should provide numerous alternate snares, kick, toms and cymbals to used as alternates in SD X-Drum feature (that is a great feature in SD).  Can't believe I bought a metal kit.
 
 BTW, I initially intended on just buying one EZX that being Indie Folk but was tempted by the two pack deal. The result is that I ended selecting two kits from opposite ends of the drum spectrum: Indie Folk and Metal Machine.  

Good choice with the Metal Machine. I haven't used it, nor have I really heard it used anywhere that I know of. DKFH however, I have heard too much everywhere. I love it, never use it anymore. Sick of it. So good choice and have much success with both Metal Machine and Indie Folk ;)