It depends on how much traveling around you're going to do. Where are you staying? I used to rent cars all the time when taxis were not very common, but now I find that taking taxis around is really easy and ends up less expensive than renting a car. Well, maybe it ends up costing the same as renting a car if you add in the cost of taking a private transfer to and from the airport.
But if you're going to be doing a lot of tours and adventures on your own, going to Coba or Akumal or wherever, then yes, renting a car is a great idea.
And Easyway is a good company to work with.
What I've been doing lately is a combination of things. I take a private transfer to and from the airport, taxis for most things in Tulum and then rent a car just for a couple of days in Tulum for off-beach adventures. Easyway has an office in Tulum right across from the new Chedraui supermarket, very convenient.
I find now that when I'm at the beach, I tend to walk to beach restaurants, so I can go for several days without getting in a car, so I hated having a rental car sitting in the parking lot going unused.
And taking taxis around Tulum or walking means you can drink more! :-)