Nextel was awesome back in the day. While their iDEN network could have been built out more, and there was no roaming expect for maybe with SouthernLinc in the Southeastern US, the concept was great. No nonsense communication. Maybe it was psychological, but using Direct Connect in lieu of the regular phone made people much less likely to blabber on and on and just get directly to the point. Very limited text messaging, no data, and those 810F Motorola phones were durable. Kinda funny to see these $800+ thin and frail wimpy smartphones covered in thick cases and screen protectors when I had probably a half a dozen Moto iDEN phones that went through hell and back and never wavered. These phone weren't fashion accessories. But these days the condom snorting, laundry detergent eating demographic that companies try to target wouldn't know what to do with a flip phone that has no QWERTY keyboard or a spying digital 'assistant', so I can see why they are a thing of the past.
Having had Sprint since the demise of Nextel up until last Fall, and having T-Mobile now, in my area and the areas I frequent, I notice no real difference, except for slower speeds with T-Mobile and no reception within a mile or so radius of my house with T-Mobile. With Sprint, I had limited reception inside the house and decent coverage outside. T-Mobile is non-existent. The coverage is so similar in general. And low frequency spectrum can only do so much good. They need more TOWERS, especially in rural areas. As much as I hate T-Mobile, and their scum bag, coked up looking used car salesman of a CEO, and as mush as I like Sprint, I have to say having three equally sized mobile providers is probably more competitive then having two big providers and two small providers that have no chances of catching up.