Originally Posted by km8j
I know all of this but they can still sell versions with different bands
Why? The unlocked version supports all of the major bands needed, including band 12, which the AT&T and Verizon phones lack.
You get Quad-band GSM, Penta-band HSPA (850, 1700, 1800, 1900, 2100MHz), and Octa-band LTE (2, 4, 5, 12, 17, 25, 26, 41).
CDMA 800/1900MHz is also thrown in.
You'll only use a few of those, mainly 1700/2100MHz or 1900/2100MHz HSPA, and bands 4 and 12 of LTE. GSM is usually 850 or 1900MHz.
With a Sprint SIM, it'll use CDMA and bands 25, 26, and 41 LTE (Spark).
With an AT&T SIM, it'll use 1900/2100MHz HSPA, and band 17 LTE (4 or 5 in regional areas where low-frequencies aren't allowed).
Why make another? It's basically a Motorola branded Nexus.
The only other versions will probably be for smaller carriers and Canada.