First off, ask around, and KNOW what you may be getting yourself into. Although MD/PhD programs are hard to get into, the bigger issue is surviving an MD/PhD program. Med school tends to require a person who can memorize and apply their knowledge. Grad school wants you to do all that and invent new things at the same time. Which comes down to research, do YOU like and motivate yourself to do all aspects of research?
If yes, then you should then ask yourself about who you would like to work with. This would be in terms of who YOU get along with, and what research area they are working on. Being happy is a part of succeeding. Research definately has its dark moments and thats when you need to rely on your devotion to the field you are studying.
In terms of the persons status at the med school. It doesn't mean too much. The person can be the dean of the med school, but it still might not get you in. The point is, the admissions committee is what it is. A committee. Therefore a bunch of people will talk about an applicant and decide on who gets in. For MD/PhD programs, you MUST get into the MD program first, and then if you are truly exceptional, they let you into the MSTP. So knowing the director of the MD/PhD program might not be beneficial in that context. But he would surely be a wealth of information on HOW to get in.
I have known friends who played golf with our med school's dean, yet they still did not get in despite decent grades. I am personally a PhD student, and do clinical research. My connections vary from CEO of the hospital to several members of the adcom. But ultimately what will get me in (somewhere) will be what I have to show as an applicant, not who I know.