For me it would depend on when you are planning on going. I lived there for serveral years, back when it was still called Estero Island, but left there when development fever took over and it became just another view of high rises along the beach.
I settled a little north of Sarasota on an Island named Anna Maria. It's more layed back, but with plenty to see and do. Since I moved off the lsland, I will be heading back for a couple of days for my RR after the World. The beach is fabulous, not as hetic getting around, a variety of resturants, shops, et...
I say the time of year, because, Ft Myers is Tropical where Anna Maria is sub tropical. So in Dec, Jan, March Ft Myers would be your best bet for warm, ( although the traffic is insane, it's expensive and crowed IMHO) but Anna Maria is perfect from April on....as far as weather, easy to get around, family owned resorts for the most part, and resturants. No Mickey D's or BK Lounges
You can check out Anna Maria at the chamber site. Tons of info on room, rates, resturants, photos, et.... annamariaislandchamber.org