I personally don't find these reasons to be very compelling.
1) "you're not viewed as real MD by doctors and you're not viewed as a real PhD by PhD's...so it's tougher to get respect"
By that reasoning, then wouldn't an MD-only researcher get even less "respect" from their PhD counterparts?
2) "there's no real way to split time between the lab and clinic...one always wins out and it's usually research."
The split generally isn't 50-50, but even if you're only seeing patients once a week, that doesn't necessarily decrease the quality of your patient care.
3) "In research, you have to basically re-apply for grant funding (your salary and research money) every 3 years or so."
Right, this would be the case with anyone pursuing a research career, regardless of degree choice. Presumably, anyone deciding between being MD/PhD or MD-only (with research fellowship) is planning on going into a research career.
4) "8 years was a big turn off, especially when that could grow to 10 if you get in with a tough advisor"
7-8 years is average at my school..~3 years extra doesn't make a huge difference. Especially if the MD-only person decides to do a research fellowship later, that would be a couple years anyways.
5) "and you can do research as an MD to the same level as a MD/PhD in 4 years less"
A research fellowship still takes time. You'd really only save about a year.
6) "you also interview with 6 people at most schools, which is kind of scary in itself, but you get used to it pretty quickly"
Sure, you interview with anywhere from 5-10 people, but then they generally pay for airfare, hotel, transportation, and meals at very nice restaurants. I actually thought the interviews were a big perk of applying MD/PhD!
