Both are great programs! I'm actually a Temple student, and I matched at MCP/Drexel... though I didn't rotate there.
I think the main differences as a 4th year rotation will probably be the patient population. Temple sees a VERY inner city/county ilke population, while MCP will probably give you a more varied population. The teaching style at both is probably pretty similar, both in lectures and clinical style, as most of the Temple attendings are from MCP. The residency director at Temple, Dr. McNamara, used to be the PD at MCP.
I can't speak for the student experience at Drexel, but at Temple you get to pretty much completely handle your patient's care, which is awesome! There is definately some scut, in the sense that they expect students to do IV's and such, but its not bad if you haven't had a whole lot of experience doing them. And, you'll get good at getting difficult IV's (a lot of the patients have pretty much blown all their good veins). You generally won't have to do transport stuff though.
Shifts at Temple are 8 hours long for students, and you work on a progressive schedule, meaning you'll work a morning shift, then a day shift, then an evening, and lastly an overnight followed by a few days off. The conferences are generally really good.
The residents at both programs are awesome... cool people, fun to work with, great docs. Both have pretty laid back attendings... first name basis with most. If you rotate at Temple, you'll get an SLOR that is a composite of all your shift evals, and Dr. McNamara usually puts some personal comments at the end of it, which is really helpful on interviews since he is extremely big in the EM community (past president of AAEM).
I really liked both programs, but chose MCP as my #1 because I was looking for a change of scenary after 4 years at Temple. I think either would be a great 4th yr rotation! If you have any other questions, PM me!