Academically, the reputation is excellent, and I'm not going to dispute that. Professors are mixed (as anywhere i would suppose) but I do feel that I am being well prepared for the MCATs and beyond... Columbia boasts a very high percentage of their students getting into medical schools. Which is great, except they don't usually mention the nearly 40% of students who don't make it through the program. So... if you make it through and do well, yes, your chances of getting into med school are high. Like with everything else, you need to take things with a grain of salt. Beyond all things, many people find the cost prohibitive and not worth it and I don't blame them. However, there is something to be said for going to a name school. I may not like it, but I can appreciate it. One thing you should look into and see if it makes a difference for you is the linkage program. For some students this is a big deal if they want the security of guaranteeing themselves a spot somewhere, or if they want to avoid glide year.
My biggest complaint about the school, as with many others, is from an administrative point of view. My advisor left after the third week of school, and this is very frustrating to me as this is the individual you should be building a relationship with because they are the one who will be responsible for writing your committee letter. Also, the postbac community is pretty big as compared to some other programs and you really have to put in a lot of effort to make sure you get the most out of your time. Its very easy to get lost in the mix.
So far I'd probably say that the educational end wins out over the problematic stuff... and while I'm not 100% satisfied, in the end, I think I'll be ok with it.