The 480GB HyperX Predator PCIe SSD's $499 street price is $200 less than the OCZ Revo Drive 350, but costs twice as much as an equivalent-capacity SATA SSD, as well as $100 more than the Intel 750 series. I'd recommend the latter if there were more widespread support for booting from an NVMe drive. If you do have NVMe boot support, the Intel 750 is the one you want.
If your motherboard has an M.2 connector there's also Samsung's new SM951, which is PCIe 3.0 (most M.2 slots are PCIe 2.0, but an increasing number are 3.0) and slightly cheaper than the Predator at the moment. But the SM951 doesn't currently ship with a PCIe adapter card. That leaves the HyperX Predator PCIe SSD as easily (cost considered) your best storage upgrade for non-NVMe/M.2 desktop systems--in other words, just about every mainstream PC in existence.
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