Back to the original question to see if I can add anything.
Gainesville's geographic location within the state is great.
It's a college city in that the campus does dominate the culture but it also has some actual real-city amenities like museums, regional theater, etc. since UF is the flagship. There's a significant amount of the population there connected to Shands, UF's Teaching Hospital and a large grad student population so it's both a UF connection and also a big demographic separate from an 18 year old underclass student.
It's also about 2-2.5 hours from Orlando, Tampa, and major beaches on both the gulf and Atlantic, and also about an hour from Jacksonville. So it's never far from a "big city" or touristy things.
Plenty of in-state kids who couldn't get to UF end up at FSU, UCF, or USF, so it's not unusual for UF students to be traveling to Tally/Orlando/Tampa to party or hang out with old-friends or hosting friends from those other schools. Your nephew would soon enough have friends/roommates with connections to one or all of those cities and an excuse to roadtrip.
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If your nephew is into outdoorsy stuff, Gainesville is basically in the heart of Florida's natural springs. Lots of state parks in the area. Activities like tubing the Itchitucknee and walking down the Devil's Millhopper are part of the student experience.
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If your nephew likes sports, UF is an "everything school" like Texas. A lot of students latch on to something other than just football or basketball. It's a great way to spend time on the cheap. My friends and I went to lots of soccer, volleyball, and baseball games.
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Weather wise, summer is hot and humid. Gainesville gets both Florida extremes. It's interior enough that it doesn't get the coastal breezes. I swear that Orlando has less humidity in August. In the winter, it's usually the edge of the frost/freeze belt.
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Like any big school, UF can be intimidating for a Freshman away from home for the first time, but there's no shortage of activities and things to do. Some kids do better closer to home or on a smaller campus. That's really up to the kid and what they want and need.