We've stayed at Hotel Ixchel and Playa Arena both on Playa Norte. Ixchel was a little nicer, hence the price but they are next door to each other so the beach is effectively the same. Arena was perfectly fine and would do that again over paying for Ixchel. The convenience for the beach and Hidalgo St is tough to beat.
The next time we go there's a good chance we'll stay here
http://villalabella.com/ as we love the bar and the grounds and there is some easter, beach access that's basically private. You'd just have to taxi or rent a golf cart to get to Playa Norte or Hidalgo. But regardless it's a must visit for Bar La Bella even if you stay elsewhere.
To me, Isla is not the place to go for AI.