what town is best

There are very few "true" 4/5 star hotels in the DR. Looks like Santo Domingo is your only option. It's more a big city than a quaint town.

Dreamer,
I'm sorry to inform you that you are posting on the wrong board. This board is for the Dominican Republic.

KW means Key West?

If you live in Key West, you are already where you need to be! But if you want something that approximates the party atmosphere of KW, is walkable, but not really quaint, then Cabarete is the place.

Tone your expectations of physical plant down a lot, though, and you will find welcoming properties on the beach--something that KW lacks for the most part.

Try Hotel Taino right on the beach, or the new Verdero condo resort on the point looking over the whole windsurfing beach. You will enjoy the atmosphere of the town, but for a little more quaint, go to Santo Domingo. It is historically very compelling, but more like Miami than KW.

There is also Las Terranas on the north coast if you want a very European beach resort atmosphere --isolated, yet somewhat sophisticated.

this may not be the right season for any of these places though.

A lot of quaint places

But dreamer wants 4-5 Stars. He will find those in the sky but not in any of the places mentioned.

Try Casa de Campo. It is about the best you can get here. La Romana is the nearest town, not exactly within walking distance, but not too far. If you are staying for a week, and you like any of the activities that they offer (specially golf) you won't get bored.

Why not get some info at a travel agency?
What do you really want: beaches, old towns, nature, culture, AI etc?
Decide and ask again!