I'll give this a shot.
PCOM's Biomed Cert. program is basically the first year of it's Masters of Biomedical Sciences program, namely the first half. You take the lectures and class curriculum (from what i understand) and at the end of it all you receive a certificate if you successfully complete. The MBS will be a 2 year ordeal where the second year will be dedicated to research, crafting a thesis, and having to do an oral defense probably in front of your graduate committee. Tuition on their website says its 701 dollars a credit, 29 credits required for the certificate program and an additional 24 credits if you choose to do the MBS 2 year program.
pros: It's PCOM? As osteopathic schools go, PCOM ranks among the top D.O. schools in the nation and I'm not exactly sure about the certificate program but its MBS program has quite a strong reputation in both D.O and M.D. schools. Location should also be a consideration. Tuition, nothing too special imo, but it's about average to possibly even cheaper in comparison to other "SMP" or post-bacc programs. As I said, I don't know about the certificate program but I have definitely read and heard good things about their MBS program from graduates.
cons: Don't know the class size, but if it's medium sized, it might be worth considering other options imo because if you pay for a D.O. SMP, I figure you might as well take advantage of a strong linkage where PCOM is known as a competitive school so you'll be competing with not only your classmates but other strong candidates after completion of the program.
If you're really into the 1 year thing and into osteopathic post bacc programs, I'd consider LECOM's biomedical post bacc, Midwestern U (AZCOM)'s MA program, KCUMB, and Barry's 1 year accelerated MBS track. Just other options that you can do research and compare which works best for you.