I have a friend at MD Anderson who completed the hemepath fellowship there. She was worked really hard, published a lot, and became a real expert in her field. She will have a great career in academics.
She did mention that they are pretty hard core. The unwritten policy on sick leave is: "If you are calling in sick, you better be calling in dead!" So even though everyone gets the virus, no one misses work, so no problem, right?
If you have the right personality, I'm sure it would be an excellent experience. Personally, I prefer things to have a little slower pace, but I'm glad that the hard-core programs are a good fit for others.