I interviewed at both and matched at UW, so I can give you a good overview of what our program is like. I had a pretty positive impression of MCW as well, but I'll leave the details of that program to those more qualified to share them.
The training here is absolutely top notch. The Radiation Oncology Department is very well respected within the hospital and the region. I haven't identified any particular weaknesses in terms of body sites (Peds is kind of hit and miss, but our Children's Hospital is currently under construction, so the numbers will likely rise in a few years). CNS, Thoracic, and Head and Neck are very strong, with Prostate and Breast not far behind. We are very active in cooperative group studies, and have a number of active protocols open in all of the aforementioned sites. We've got a bunch of cool toys (Tomo, dedicated CT/PET, etc.), and are very active procedurally (I've got two HDR's today, prostate implants and APBI are going on all the time).
In terms of reputation, we are usually mentioned on the fringes of the "elite" programs. We don't get the same kind of love that MSKCC, MDACC, JCRT, Mich, Stanford et al. do, but I think practitioners in the field have a tremendous amount of respect for the work we do here. The program is very stable at the top; Drs. Mehta, Harari, and Ritter are not going anywhere soon, and the attending mix is nice with the recent addition of three younger faculty who are fresh from their boards and just outstanding teachers!
We have a busy clinical schedule. I'd estimate we have about 75 people on treatment at any given time, and residents will typically see 10-12 new consults per week. We have morning conferences two days a week that are now run "Cleveland Clinic" style. Everyone prepares for the topic in advance, and one person prepares a "buzzard-style" handout. Let me say this: Cleveland Clinic has IMO an undeserved reputation as a "malignant" program based on the pimping that goes on at their conferences. I attended one on interview, and have now been through about a dozen here, and they are tremendous teaching tools. No one is made to feel bad at these sessions, and you will be amazed at the amount you learn in a very short period of time. There is definitely an expectation here that graduating residents will have an excellent body of knowledge to take with them into practice, and I think it shows when you look at where recent graduates have landed jobs (MDACC, JCRT, MCV, etc.). The faculty are equally supportive of residents going into private practice, as both of our current chiefs will be doing.
The thing which I really love about this program, though, is the atmosphere. Everyone is very friendly and laid back. Residents are on a first name basis with the attendings, the relationship between us and the surgical subspecialties is great; we are considered equals in every regard, even with urology! Madison is a great town (haven't been through a winter yet, though. I'll let you know how that goes...), and the hospital itself is beautiful.
I am happy to entertain any further questions about UW, either on this forum, or on PM. For all the applicants out there, don't let the cold scare you, come check us out!
--BTW, Steph, if you run into Ted Hong over there, let him know the crew here says hello.