Always go with your gut imho.
Anyway, PBL might be a pain (I never did it so I don't have an opinion either way) but it'll only be during the first two years afaik, and then after that you're out on placement anyway.
As for how rigorous it is, well that depends on you. Perhaps it's not as didactic as lectures, but if you're the sort of person who's quite lax and puts in the bare minimum when it comes to studying, you'll find a way to be procrastinate even with the most traditional course in the world. I think a lot of this comes back to you as an individual - if you want to learn and do well, you'll settle into PBL and do well anyway. In short: don't let minor differences and semantics put you off!