Per my wife: You don't care for fellowships at programs that aren't top 10-15. You can go anywhere for fellowship even from the lowest-tier schools. The program matters very little. Every PD will put in a good word for you, and every PD has connections to those top 10/15. You're living here for 4 years. You want to learn, and have peace of mind.
-Valhalla caters to both independent self-learners, those who want to go home early, those who want to stay late, those who want extra help, etc. Also, valhalla is pretty prestigious to work at for attendings. A lot of attendings want to end up working there, which means they are REALLY happy. And you will see plenty mix of attendings, from MGH, u of c, Columbia. (I should note that I'm from this area, and done rotations here, I'm really trying not to have a bias, but I know a lot of the negatives about the hospital and to me it's just really not. that. bad.)
-Mt Sinai, despite the extremely high cost of living and the fact that every resident is barely getting by financially, the program is extremely robotic and stressful. Staying until 9 grossing, weekends, attendings making unreasonable demands, this is a serious heart attack program. The attendings are savage and will report you, and it rubs off on the residents relationships with each other. This results in the biggest problem: FAKE SMILES. "I know you felt it while you were there. Bunch of dead eyes and big smiles speaking like robots. I felt like I was in a black mirror episode at this program. Pretty resident room tho."
-Loyola, again, not the best part of Chicago, pathologists are kinda treated like crap. I interviewed here for DR. The suites were NICE. I've done prelim iv here in the IM department. Beautiful! My wife's exp in the pathology department, well let's say loyola doesn't really care about the path department. You will spend half your time (CP rotations) in the basement with no cell phone reception. They have an attending there that everyone looks up to and is actually one of the main educators, he has an eastern European accent. My wife said during the interview he just talked smack about the program and basically suggested she keep looking elsewhere because the interview day is a day of hiding all their skeletons. That holds true for every program, but she doesn't want to go to a place where the attendings don't want to be there.
As for your second question, My wife really wanted the interview but didn't get it but said her friend got it. She didn't like the interview at first but went for a second visit and a completely different vibe from Houston and it's now her number.