I'm still on my NS4G and I'm battling with the same issue. I've worked it down to this. I love Nexus phones (even through this CDMA-Nexus-Google nonsense) but there's no doubt if the One X variant on Sprint will blow the Nexus away as far as horsepower. Bear in mind the Sprint variant will not be quad-core. It'll most likely be a 1.5GHz Dual-Core. (Google Qualcomm Cortex-A15 "Krait")

The One X in this barebones situation would be the obvious choice, but consider this; All of the leaks for the "HTC EVO One" give descriptions of a phone that is not a true One X. We're talking kickstands (thicker phone), carrier bloat, and MicroSD slot (even thicker.) The internals may be similiar to the actual One X, but if these turn out to be true I'm going with the Nexus. I want a One X, not a Sprint "lets make it bigger and bloat it up to match the EVO brand name" One X.

Time will obviously tell, but as of now hardware wise, the Nexus is about in for a rude awakening from the competition. That and HTC is putting out updates for devices faster than Google and Carriers are pusing updates out for CDMA Nexus devices.