So, you might choose the HTC EVO 4G LTE and see LTE coverage in an area, or you might choose the HTC EVO 3D and see WiMax coverage. You might even pick the HTC Arrive and see neither, as that device supports Sprint's 3G (CDMA) only.
While it's a good idea, it's a better idea going forward. After all, if you look at current maps, you'll see no LTE coverage - anywhere. Sprint's LTE phones, therefore, are stuck on its relatively slow CDMA service.
Sprint made the decision to switch from WiMax to LTE last year. Of course, one company that it had backed last year when it announced the change, LightSquared, has since seen its fortunes turn to dust.
Most importantly for Sprint's future: it needs to get this rollout begun and burgeoning before the release of the iPhone 5, which is expected to support LTE.