Crown Park is brand new - they still have an active sales force and will call you to offer a tour (we did NOT take the tour). The accommodations were very nice. We had a 1BR and it was well appointed although a little on the small side.
Tree Tops is a much older resort with all 2BR villas. It is on a stream in a very wooded area. It's a beautiful location but too far to walk to get into G'Burg itself (it's a 3 minute drive though). I would suggest taking the Motor Nature Trail - it cuts thru a remote area of the Park and has a number of hiking trails as well as some old buildings to see. Tree Tops is located at the exit of the one-way motor trail.
We've been going to Gatlinburg since the late 70's and have watched the community grow with mtn. chalets, timeshares and resort and restaurant chains replacing the local cabins, restaurants and stores. In some cases, the changes are wonderful and in others, not-so-much ... but we continue to return at least once a year and usually more often.