CSR's pool is incredible but IMHO and my kids', so is POR's. For the age of your boys, I think POR's main pool would be a winner. My son (11 when we stayed at POR), loved it that they had these huge bucket type things that poured water down in the pool in a massive sort of way! He also thought the slide was pretty good. And I for one like it that at POR, (and CBR and POFQ for that matter) the food court is next to the pool. I can understand why CSR's isn't since Pepper Market is not your average food court and they have a lot of business travlers that don't want to be dining with people in their swimsuits but it bugged me. The pool bar had food at CSR but it was limited in selection.
POFQ's pool is better for little kids in my opinion. Its smaller and since this resort has no quiet pools it fills up fast. I think your kids might be bored with this one.
CBR's pool slide was not as great as CSR's and POR's according to my kids but the pool itself was very nice. Also CBR's quiet pools were the nicest of any of the mods in my opinion. And having the beach right there too is also a winner. CBR is my favorite mod, but POR's pool wins by a hair. Also, I belive, CBR's main pool is about to be rennovated so that should be checked into for ppl thinking about staying there.