It really depends on what you're looking for. Some will love it, some will hate it.
Pros
Fantastically friendly people, long tenure (tons of knowledge about the company and wireless industry. Generally fairly laid back culture. Good work-life balance for the most part. Nice mostly remote/hybrid work environment (I go in to the office maybe once a month). If you're just looking for a decent paycheck, have minimal ambitions, and want work-life balance, this is a good place.
Cons
The biggest con is the highly political, rigid politics. This plays out in several ways. Managers and others several rungs down on the ladder are not "allowed" to talk to senior leaders about anything work-related, even if it would make work more efficient. It seems like absolutely everything has to be run up the chain of command regardless of how significant it is. This is a real motivation killer and it keeps a lot of quality ideas and work from ever getting off the ground. This also leads to extreme title deference. There's this idea at UScellular that because someone is a director, or a senior director, or a VP - or whatever - who has been with the company for 10+ years, he/she has earned the right not to have pushback or questions. What's especially aggravating is that senior leaders themselves don't often think this way. The CEO certainly doesn't. There's a huge layer of middle management that gets in the way of valuable work just because of politics. This is not the place to work for people who want to make big contributions quickly without suffering layers of bureaucracy.