The Sheraton Grande Laguna was a bummer. Over priced, food was lousy, too far from everything.
Yes, one of my friends stayed there once and said the same. They felt cut off from everything else on the island.
Resorts like that want you to stay at their place and not go out to spend money anywhere else. You might as well stay on Coral Island - there's nowhere else to go but at least it's a nice island (fairly cheap too considering you can't go anywhere else). I actually prefer staying on Phuket itself though as there's a bit more to do and if I go out for dinner at night and haven't been hassled by at least 10 tailors en route, I feel like my holiday hasn't really got going!
We usually stay in the south - Nai Harn is one of the beaches I like the best followed by Kata Noi. The main Kata beach is OK but Club Med dominates that beach and it kind of ruins it for me - I like a beach with a bit of life; restaurants and shops along the road and interesting things to look at; Club Med is like a condo - just a fence all along one side of the road. But that's what places like the Sheraton should do if they want people to stay there all the time - advertise is as an all inclusive place instead of trying to imprison their guests!
But Kata is once of the more interesting places to stay around Phuket. It's full of small shops and restaurants - it's busy and fairly lively without the seediness of Patong at night.
Koh Lanta is a nice island though - try that one next time. The beaches as I remember them aren't that great for snorkelling (too sandy, not enough rocks) but very nice sandy beaches. You can can get a speedboat trip to Koh Rok and that's got the most beautiful snorkelling and beaches I've seen around Thailand so far - clown fish, loads of coral, sugar white sand and no resorts on it so very unspoilt (or at least it was!). We went about 6 years ago so things will no doubt have changed but unlike Phuket, on Koh Lanta I believe they're not allowed to build higher than the height of the palm trees so it's mainly small bungalow resorts right by the beach (and you don't get many of that kind of resort in Phuket sadly).
It was the kind of place where you didn't really need to wear shoes - you just walked along the beach barefoot watching the sun set over the Phi Phi islands while you chose which place to go and have dinner. It was a very relaxing holiday and hopefully we'll go back there again one day.