I know a good amount about the UT Houston program and will comment with my thoughts.
I am not sure where people keep getting the "residents are unhappy" vibe. I spent about 3 months doing rotations there and am still trying to think which unhappy residents people keep bringing up. There are some residents that may feel they deserved (because many derm applicants think the world of themselves) to match at a different school and are unhappy that they ended up at UT Houston, but it's a silly assertion to make. If you wanted to match elsewhere "more competitive", then you should have done better on step/done more research/better letters/etc etc..
Overworked is a very funny phrase to use here, as they get out around 4:00-4:30 from the county clinic, 5-6pm from the Houston derm clinic. The only place I can think people feel "overworked" is Dr. Duvic's clinic where days usually end at 7-8pm. However, that clinic happens only twice a week and it's for 2 months for PGY2 and PGY3. The flip side to this is getting to learn from one of the best clinicians and researchers out there. Her clinic runs 2-3 hours behind, but her patients rarely complain because they know who they are about to see. She also makes you write detailed notes and do an actual physical exam (skin surface area etc) because, well, these patients are complicated and it needs to be done. In return, you get to see things in that clinic that most people will only read about. I can go on and on about this, but the end idea is that you learn to become a competent clinician while working with a physician that pretty much every dermatologist knows in the US (she was brought up in almost every single one of my derm interviews this year without me mentioning her).
MD Anderson is an invaluable experience and not just an association that UT Houston uses for its rankings. Residents spend a significant amount of time there doing general derm clinics and the attendings there are quite young and love to teach. There is no VA at UT Houston, Baylor has it. I did a few aways at programs that have VAs and honestly would take MD Anderson over a VA anyday. I think a VA is important to have when a program lacks a county clinic, but that's not a problem at Houston since QM is very busy county clinic.
Many of the residents that go here that went to UT Houston for medical school are extremely competitive (high step scores, 10+ derm interviews, AOA etc), but many end up staying because they legitimately love the program. From what I have heard, the interview day is not super well designed and that's unfortunate. On my interview trail, everything blended together so much that at some point anything that seemed negative to me quickly brought the program down on my list, and I assume that's why some are turned off.