Even though this response is really only functionally useful to people in the U.S., I'm going to give some background so that my fellow non-American LMF users can follow along with this discussion if they like, and also so they might be better informed about how to handle their own smartphone needs when traveling here.
Hintergrund / Background:
There are two kinds of cellular networks: CDMA and GSM. Originally developed in Russia, CDMA was designed to have a relatively sparse cellular tower network and have coverage over longer distances. GSM was developed in Europe and had the in-built expectation of having a fairly high density of cell towers. Nearly the entire world solely uses GSM, except for the U.S., which implemented and continues to use both. What has happened over about the last 15 years is that GSM is slowly winning out over CDMA because of all the cell company mergers. Classically, Sprint, MetroPCS, Verizon, and some other small fry were/are CDMA carriers, and T-Mobile, AT&T, and others were GSM. Now that most of those have been folded into just a couple businesses, pretty much now the three major cell networks across the U.S. are AT&T, T-Mobile, and Verizon.
From the perspective of an individual wanting to get cell service, there are quite a number of choices. That said, there are basically two kinds of service providers you can pick from: actual carriers themselves (again, mostly AT&T, T-Mobile, and Verizon) and
Mobile
Virtual
Network
Operators, or MVNOs. MVNOs, for those who are unfamiliar, are third party resellers of cell service. There is quite a long list, but include Cricket, Straight Talk, Ting, Mint Mobile, Tracfone, and Consumer Cellular.
In general, you don't need to have a credit check done, nor do you have to even have permanent U.S. residency to get service. This is particularly true with MVNOs and real carriers with pre-paid service, such as AT&T.
Ok, so what about me? What have my experiences been? Who would I recommend?
I've been a customer of Sprint and really used to like them and their service. However, they ate me out of house and home, so I walked away from them somewhere around 2012. I've briefly been a T-Mobile customer. I was an AT&T customer for a year, and presently I'm a Ting Mobile customer.
Customer Service-wise, I've been the most happy with Ting, which is also my present provider, out of everyone mentioned above. They use two different carriers' networks — T-Mobile (for phones capable of GSM) and Verizon (for phones only capable of CDMA) — and for $35 a month I get 12GB of 5G data, and unlimited talk and text.
I had Straight Talk for several years. Initially I used them on T-Mobile's network, but ultimately switched to the AT&T network for better coverage. They kept upping their monthly data allotment, so ultimately it was 25GB a month of high-speed (non-5G) data for $45. I decided I wanted to try something different, so for a year I went with AT&T as a pre-paid customer and had the 6 month version of their
pre-paid 8GB month plan.
My complaints with Sprint were twofold: cost, and coverage. To be honest, it could be pretty spotty at times. Also, when the rest of the industry went with LTE, they backed WIMAX, and that choice plus how they decided to handle things just about cost them their very existence. At this point, they don't really exist any more because T-Mobile bought them up.
When I was briefly a T-Mobile customer (about a year) the only issues I ever had were coverage. Honestly, it wasn't as good as AT&T.
Between 2014 when I left them for Straight Talk and Q2 of 2021 when I went back to their network as a Ting customer, a LOT of things have changed, chief among them is coverage. It's arguable if it's as good as AT&T, but it's insanely better than it was.
