hey,
I'm in my 5th year of my Ph.D in immunology (hence the name). A Ph.D. is a training degree for a career in research. Research is an awful career with respect to money, security & lifestyle for all but the lucky few who make it to tenure without dropping out or loosing funding.
I can not stress this enough.
The few professors you meet are the cream of the crop, most of their friends that they entered their Ph.D. programs with are likely no longer in research.
Go for the MD or DDS as if your life depended on it. Otherwise you may end up like me; a grad student who after 6 years will have graduated with a degree that requires you to then do at least two 3 year post-docs ($35-$40 /year) before entering academics ($60-$80/ year). 12 years total.
Go for the MD or DDS.
I just got home today, and heard another message on the answering machine for my wife. About 4 times a week she's getting calls offering her jobs. Good jobs. Jobs you can take out a huge mortgage on and still save for retirement/kids/cars/fun.
Guess which degree she's got?