We had a 17ft Casita for 5 years and pulled it with a Ford Explorer with the small V8. If you are going to pull in the mountains you may be happier with an SUV with a small V8 although the newer V6s are probably adequate.
The only thing I wish we had done is use an weight distributing hitch to distribute the trailer weight better between the front and rear of the TV. I brute forced the TV squat with Monroe coil spring over shock which was OK but it made the unloaded ride harsher. Ours had the resedential window A/C mounted under the front closet which made the tongue weight higher than the current ones with the roof mount. I would still recommend going with a weight distributing hitch for more enjoyable towing experience.
Dick