It really depends upon where you live, how many cell towers, how far apart, are there mountainous areas creating interference, etc.
What you should try to find out is whether any of the local media have done studies on which carrier provides the best service for that area. Many times they do an annual “Best Of…” in numerous categories.
Philly Magazine does one every year and it’s their best selling issue.
Sometimes a local magazine or newspaper does such a study; other times it’s one or more of the local TV stations.
Check around your area. I also know that Consumer Reports does surveys and studies like this, but I believe you have to have an active membership to access the details pertinent to your area.
If you’re fortunate enough to live in or near a major metropolitan area then most is the major carriers are pretty much equivalent so then it becomes a matter of comparing on price and terms of contract.