As others mentioned accepted rates are all those extended acceptances, # matriculated is different. Each schools knows more or less how many acceptances it takes to fill the class (and how long to make the waitlist). The U, at least in the past, has virtually offered acceptances to only as many people as they have seats and used the wait list from there. They have one of the highest matriculated/acceptances ratios in the country (don't have time to cite that but should be easy to find). As for the mediocrity, *shrug* some may think so, I don't find that to be the case but I'm of course biased. I personally find it awesome, I've loved my research opportunities, the service opportunities, outdoor activities (I'm a mountain biker hard to beat the local), and my classmates are amazing (instate tuition is a nice little cherry on top as well).
As others have mentioned it's a personal fit, in the end when it comes to matching, or getting the most out of your medical school time (whatever that means to you), much of it comes down to your own efforts, preferences, goals, etc., so wherever you feel best arms you to meet your needs will likely be where you're most interested.