Whudup1 - You are in a very similar situation geographically as I was. It is 4.25 hours to Mayo-Rochester and 45 minutes to the University of Iowa. I looked at both and decided to go with Mayo-Rochester.
From the research I did, surgery success (cancer removal/containment, post-surgery side effects, etc.) are directly correlated with the doctor and surgical center staff competence. Both the University of Iowa and Mayo-Rochester are excellent facilities. I chose Mayo-Rochester for several reasons - The most important being my doctor (Dr. Igor Frank), he was focused on prostate and bladder cancer, versus other doctors that specialized in a wider variety of cancers/illnesses/surgeries. Also, Dr. Frank had performed the robotic radical prostatectomy for over 15 years, which gave me a lot of confidence in his ability to make competent decisions throughout the surgery (nerve sparring, lymph node removal evaluation, etc.

My wife and I decided to stay in Rochester for two weeks following the surgery. One week would have been fine (post catheter removal), but we wanted to be close to Mayo in case there were any complications. The cancer team at Mayo has a list of great rentals at a reduced rate. We were able to get one within 4 blocks of the Methodist surgical center.

Best of luck with your decision,

Jim