well yes and no. lol. the difficulty in med school classes (at least 1st year @ g-town) is not challenging subject matter, but rather the volume and speed that you go through the subject matter. as an overall experience, i personally felt it was worth the money although there are those who don't feel the program helped them. yes it can be cut-throat. the gunners popup early and go strong, but at least for my class we were all very helpful, finding extra resources, studying together, etc. so it didn't feel like this giant competition.
i suppose it's more what you feel comfortable in doing. the SMP is meant to help people with average MCATs and low GPAs demonstrate that they are capable of excelling in medical school despite a low GPA, not to mention after all is said and done you get a M.S. as well as get to live in DC whereas upper level post-bacs may be able to increase your GPA, there is no way those classes can match the closeness to actually being in medschool, nor the overall experience. IMO.
in short, i loved it. and i didnt even get into medschool right out of the program last year 🙁
if you are really interested and have concerns/questions i would call either dr.myers or ms.cabiness because they are really helpful