Mach Xtreme (MX) is so new to the memory market that the dust has barely had time to settle, and nor does it appear to be doing so any time soon - MX has hit the ground running with a dual-channel memory kit running at 2300MHz with 8-11-8-28 timings. At these XMP profile settings we noticed slightly better wPrime scores and slightly lower PiFast scores than the G.Skill Pi series kit , though they're very similar.
Overclocking was much improved due to the unique heatsinks on the two sticks (each mounted in an alternating fashion so they can be installed side-by-side), boosting the frequency up to 2520MHz at the maximum. We even lowered the timings somewhat and kept frequencies higher, though the best result is hard to call - 2520MHz seems fastest, but potentially due to the overclocked processor.
For $220 this kit is the fastest we've seen yet, shaming slower triple-channel kits, though you need to tweak them heavily to get them to their best. We give this kit a HOT 9.0/10.