Most of the Knoxville students that I've met have said the same things that
@Ostkoshbgosh and
@premedmommyx2 said. Instruction goes back and forth via webcasting, and plenty of people don't go to class in favor of just watching recorded lectures, so not too much of pro/con there. Harrogate is more established, but all that really means is that the facilities and procedures have been around longer and they're on LMU's main campus, so they have more resources in terms of student services (access to the gym, the pool, the cafeteria, the counseling center, etc.), but those resources aren't as important to most graduate/professional students that I know of. Some people use the gym and people use the counseling, but it's not really a big deciding factor for most people in terms of which campus they want to go to. Still, some people would rather feel more secure in not being one of the first classes of a new campus, which is perfectly reasonable.
If you have a support system (that you're not actively trying to escape) in Knoxville, that's probably a really good reason to request that campus. But if you're used to a small town and you want to stay in that kind of environment, there certainly aren't as many distractions in Harrogate. It's about personal pro/cons, so definitely visit both campuses if you're on the fence.
Can our current Knoxville students speak to student services on that campus? I heard rumors that they were going to put in a gym, but haven't been up that way in awhile. Obviously there are gyms and services all over Knoxville, but did they put anything in on campus or offer any free* services to students?