Cell phone coverage question - AT&T vs T-Mobile

Since cell phone coverage maps all look the same, I figured I’d ask real users about their cell phone coverage. I live in Boca and work in Broward. I currently have AT&T. There are some absolute dead spots in Boca where I get no coverage at all. Looking to change to T-Mobile (had a bad experience with Verizon). I’ve been hearing great things about T-Mobile. Is it really better than AT&T? Is it worth switching carriers?