When you say "Do you feel there is any difference between receiving the MD from Harvard, Columbia, U. Penn, UCSF, UCLA, etc?", I don't know if you are asking if the quality of the training will be different or if your competiveness will be different.
As for the quality of the training, it totally depends on what field you want to go into. Programs like Bascom-Palmer (UMiami) and U Cinncinati are at the top for ophtho and emergency medicine, respectively. If you want to go into either of these fields, your training at those places will be top-notch. That "may" not be true for other fields.
If you are asking about your "competitiveness" upon graduating...
*it should be noted that most residency programs REALLY favor their own students.*
With that said, it all matters what you want to go into. To use the same example, if you go to U Miami for med school, this may not seem to be "the most prestigious", but you may be able to set yourself for an amazing ophtho residency. And since ophto programs are really small (around 5 people/year), there is guaranteed to be very good applicants at Harvard, Hopkins, Penn, etc who want to go to Bascom but will not be able to. Not a very big deal for them, because they will certainly get into somewhere else that is very good, but it would be sad if they were dead set on going to Miami.
In terms of "general competitiveness", it is only meaningful to place schools into tiers. Within a tier, residency directors do not differentiate between schools. The following is my assessment, supported by the internal medicine program director at my school, and supported by the applicant experience of friends and acquaitances at other schools who I met on the interview trial.
Tier 1: Harvard and Hopkins are probably in a class by themselves.
Tier 2: UCSF, University of Pennsylvania, Duke, Stanford, Washington University, Columbia P&S, Yale, University of Washington, UT-Southwestern, University of Michigan, UCLA, Vanderbilt, Cornell, University of Chicago, Baylor, Mayo
Tier 3: University of Pittsburgh, UCSD, Northwestern, Emory, Mount Sinai, New York University, Case Western Reserve, University of North Carolina, University of Virginia, Boston University, University of Wisconsin, Oregon HSC, University of Alabama, University of Colorado, Brown, University of Rochester, Tufts, USC, Dartmouth, University of Iowa, Albert Einstein, University of Maryland, Georgetown, Wake Forest, Thomas Jefferson, Tulane, University of Cincinnati, Ohio State, University of Connecticut, UMass, Indiana University, UC-Irvine UC-Davis (i'm sure I forgot some)
Tier 4😛retty much everything else
Of course, if you know you want to go to Columbia for residency, then you have an advantage if you go to Columbia over an equal program like Penn. Also, if you know you want to be in NYC, you will probably be at an advantage to go to a NY med school because, like I said, it gets really small and there is a better chance that residency admissions officers will know people you have worked with.