We did a snorkeling excursion in Cabo - can’t remember which one, but it was just Ok. I will admit that we we thought Cabo was one of the most annoying ports we’ve ever visited between the super aggressive locals at the pier and pretty much everywhere in town (in addition to the hard sales pitches, be sure not to fall for the trick where they try to force you or your kids to hold an iguana then insist you pay them for that privilege), and the overall college spring break vibe that we outgrew quite a few years ago.
In Puerta Vallarta, we did Yelapa & Majahuitas (PV28). We enjoyed the places we visited (good snorkeling, a neat little town and a very pretty waterfall). But it was a long day, totaling about 3 hours out and back on the catamaran, and the hike is pretty hilly so you need to be prepared for that.
Hope this helps!