Are there any other pools worth checking out (at the other hotels, not VB)?
Hard Rock has a decent slide, and it was a little less crowded than CB when we did a split stay back in April. There's also the underwater music in the HR pool. My youngest put on her life jacket, and just floated on her back with her ears underwater, listening to the music play. Overall, I didn't find it to be objectively better than CBBR, but it did seem more upscale, and less noisy.
That said, I'm not sure how much pool hopping happens in practice. IMO, the chances are pretty slim that someone staying at HRH, RPH or PB would want to catch a bus over to CBBR and deal with changing into/out of swimsuits and a bus back when there are perfectly good pools at their own hotels. Maybe they'd take a quick walk between those three to get a different vibe, but I don't imagine many make the trek over to CBBR. If you had a free day, it might be fun to hop between the three of them. Alternately, their close proximity to the parks makes them a tempting option for an afternoon break that doesn't involve bussing back to CBBR.
Aventura guests might want to wander over to CBBR, but I get the feeling that Aventura has a more adult vibe, and guests there are less likely to want the lively, noisy family atmosphere of Cabana Bay. Since Aventura and CB are usually priced the same, I think people self-select into the type of resort they want. Aventura's pool is pretty basic, but if you're an adult who wants to sit undisturbed on a lounger with a drink, you're going to prefer Aventura. The pool itself isn't a draw.
There could be some interchanges between Sapphire Falls and Cabana Bay because SF has a great pool, but a more tropical relaxing vibe to it. Given the proximity, I think it would be easy to hop over and check out the other. IMO, this is the best pool hopping opportunity because the pools are both very well done, but very different.
Endless Summer guests are not allowed to pool hop at all. Their pools are extremely basic and shallow. Good for a quick dip in to cool off, but not great for people who like serious pool time. Given the huge size of the hotels, and the relatively small size of the pools, the pools are really inadequate for the resort. I have a feeling the prohibition on ES guests pool hopping is likely to stick around because those are the guests who would be most motivated to seek out another resort's pool.