I'm currently an intern at MCW, so I can't speak from first-hand experience about the CA-x years, but from my observation I'd say MCW is similar to CCF described above. By no means will you be getting out of the OR at 3:00 every afternoon M-F here--and I don't really know that that's such a great benefit either. But none of the residents I know are routinely breaking hour rules or anything like that. Seems like typically things are more in the 65-70 range for weekly hours, which is definitely doable.
I can speak from personal experience regarding our intern program (for the categorical program, of which about 85+% of our match spots are) that it's VERY good. You get a nice mix of medicine, ICU, surgery, ER, plus a month each of OR anesthesia, pre-op clinic, and pain clinic. The latter three months are all M-F with normal hours. I'd say counting all months, I've averaged about 65 hours per week on my intern year, which ain't bad at all. That's including pretty heavy months for medicine wards, cardiology wards, and CT surgery.
I asked the same question about MCW being a workhorse program here on SDN prior to ranking it, and it's hard to get good answers because people will sometime exaggerate, post especially negatively or positively for ulterior motives, and because programs change. I can't say for sure, but I think there's some of the latter at MCW. I know there's been a push in the administration over the last several years to reduce grunt work, keep everyone in check with hours, have more didactics (which I've been pleased with so far), and save more time for reading. I think possibly with the softening CRNA market, they recently hired some more CRNAs to help with overnight call to help with hours, and supposedly this has made some positive differences.
I do still hear from residents that your months at Children's Hospital (of which most get a few throughout the three anesthesia years) are the hardest, and you will hit the work-hour limits there. But I'm sure just about every program has their few rotations here and there that are tougher than others.
Anyhow, I would just take everything you read about programs with a grain of salt and try to go by what the current residents say--because programs really do change every few years depending on leadership, trends in the field, etc. I will try to post again after next year once I have some first-hand experience, but as of now, I have no evidence based on discussions with residents and observation that MCW is what I'd call a "workhorse" program.
It's DEFINITELY not the easiest program in terms of hours, but you're not going to be violating work hours, routinely working 'til midinight, or performing tons of scut work either. Think somewhere in the middle as far as anesthesia programs go. And the intern year isn't too bad either.