What holds up
The geography is the main one. You are inside a reasonable drive of Brian Head, Zion, Bryce and the interstate. Southern Utah University brings a cultural life the town would not otherwise have, and the Utah Shakespeare Festival is a genuinely serious institution for a place this size.
What surprises people
Winter. Cedar City sits at elevation and gets weather that St. George does not. If you are moving up from the low desert, that is the single biggest adjustment, and it is worth visiting in January rather than only in July.
The practical stuff
It is a small town. That means shorter drives, fewer options, and a business community where reputation travels quickly. Whether that reads as a benefit or a limitation depends on what you are coming from.
Before you commit
Come in the off season. Drive the route you would actually drive. Southern Utah is easy to fall for in good weather, and the people who are happiest here are the ones who saw it in bad weather first.