Isla Mujeres is definitely worth a visit. But save it for when you can stay on the island for 3, 4 or 5 days. Stay on the north side of the island. And be ready...
Heck no Im not walking that, even with Sam!
The cost is cancer, death, copd, emphysema, circulation problems the list goes on and on.
Its not stressful renting a car in Cozumel if you rent from a reputable dealer like ISIS Rentadora or Fiesta with Veronica. The roadway on the island basically...
Anywhere you can sit, eat and watch the sunset.
I shall recommend Rolandis.
Go direct, do not rent a car from a 3rd party website.
And thank you for the link to the cam.
It might only be 100 yards wide but that is the nicest beach on Cozumel. I'm not even kidding.