The OCZ Reaper HPC series for the i7 platform really combines the best of many worlds. On one hand you receive memory, which manages to run well at the low voltage required for the Intel chip, but you also get great overclockablity if you are willing to push the memory further. This should make the Reaper interesting for hardcore overclockers wanting to tickle the most out of their system. On top of that OCZ manages to offer the memory at prices which are usually intended for CL9 parts from other manufacturers. So you are getting some great memory for your money.
There are a few downsides, which can at most be considered small annoyances. First off is the fact, that the memory actually needs more than the default 1.5 V to run at the rated speed. This is not a big deal, because 1.65V has become the defacto "default" for i7 systems anyways. Second, the heatspreader design may be very appealing, but will block large CPU coolers on some boards - as was the case with our Foxconn Bloodrage. That said, you really cannot go wrong with the OCZ Reaper HPC kit. 1866 MHz is a nice sweet spot for those wanting to push the CPU above that 3.6 GHz mark everyone else and their dogs are running their i7s at, while still giving you plenty of interesting voltage and latency constellations to play with.