I have been packing it, but I never dive with it. I hate the drag, entanglement issues with kelp, and the painful clips. I knew a guy that had his mask stolen at 60' by a seal in the Coronados. The seal grabbed his mask by the snorkel.
I have had surface swims, especially on beach entries, that would have been more fun if had a snorkel instead of swimming on my back and reversing my compass heading. I also like to look in the water when I enter. Some Florida surface swims can be 300 yards or more.
In a recent heavy kelp dive, I was able to return to the boat avoiding the kelp problems, by swimming at 20' solely by compass. We couldn't even see the boat or its shadow, but we somehow ascended right at the boat, midships! Actually I can probably swim faster underwather than at the surface. The Apollo fins are fast.
I just ordered an Agualung Snap roll-up snorkel that I will be carrying on dives, maybe in my pocket. Leisure Pro has it on sale for $14.95 right now.