For probably 10 years I used Sprint because they consistently offered the best price and perks despite not having bought up as much coverage in some areas as VZW and ATT. When I used a flip phone in the early 2000's I could get service for dirt cheap. A few hundred minutes plus a few hundred texts (back when those were itemized money makers for carriers) for $30/mo. When I got my first smart phone, a Treo 650, unlimited data was another $10 or $15/mo addon which brought my total to around $40-45/mo.
I never worried about minutes because Sprint didn't count any calls made on weekends, any calls made after 7pm, or even any calls to/from any cell phone of any carrier against your balance. Early on, the data speeds only allowed me to check email, sync calendars, and stream 128k/s Shoutcast streams in the car but I already felt like it was "futuristic" while friends were paying monthly fees for XM Radio or pricey Blackberry plans.
With my second smartphone (an HTC PocketPC running Windows Mobile) I got GPS navigation, unlimited 3G service at around 600-800k/sec, and all the cool stuff that came along with it like the ability to stream live TV from my PC with a tuner card at home. Data was still unlimited and my monthly bills were under $50. As a longer-term customer, I got a new phone subsidy every year instead of every two years at a time when there was no real benefit to going without a contract to save money.
Coverage in rural areas wasn't anywhere near as good as the bigger carriers but I lived in the city and Sprint roamed for free on Verizon towers so I could always make and receive calls. As the non-early-adopters started buying smartphones, I was always amazed that friends were paying upwards of $90/mo for iPhones on ATT with limited data and 2G speeds.
When WiMax debuted, our city was on the list of the initial rollout cities and I was using my phone as a WiFi hotspot to get (at the time) amazing 5-8mbps speeds anywhere I went. Video calls and live streaming video were now a thing and even though the monthly cost jumped from $45 to $60 it was still cheaper than alternatives.
But then they got rid of yearly subsidies. And the prices went up as they reorganized their tiers so that the cheapest plan I could get included more minutes that I could ever use with no way to buy less. $80/mo was creeping dangerously close to ATT/VZW prices. I still had unlimited data but over time, those 5-8mbps speeds weren't showing up on my actual phone. I was in a full coverage area with excellent signal but lucky to break 1mbps during the day.
It was a tough time to be a Sprint loyalist as service was becoming more expensive and less reliable. The tipping point for me was the Nexus 5 and TMobile's semi-hidden prepaid options. In the past Tmo had seemed like it was roughly the same in terms of cost but they had less coverage. But now I could buy a good phone off contract for $350 and pay only $30/mo for a 5GB data allotment with 100 minutes (which is still more than I use normally but much better than paying for hundreds).
When my Sprint contract expired I made the switch over to TMo and cut my bill in half. I've got WiFi coverage at home and at work so I never go over 5GB these days. If I run out of minutes for some weird reason, it's a quick couple of taps and $10 to add another 100 minutes. If Tmo ever pisses me off I can just buy a SIM from someone else and be ready to go. And the only downside is that I get no service in more remote areas.
But since I am in the city for 98% of the year, I figured it was a worthwhile tradeoff. Data speeds are excellent and I'm not stuck in a contract paying 2-3x as much for unwanted services. I don't know what it will take for Sprint to bounce back short of a TMo-like reinvention. The problem is that the things that attract me as a customer (cheap, fast, contract-free dumb pipes) are not the things that make loads of money for carriers. If they are able to leverage the amount of fiber and spectrum they own at good terms for customers, I'd gladly consider them again. But for the time being, I haven't felt like I was getting this good a deal since my early days with Sprint.