Just keep in mind you often get what you pay for.
What are you expectations/goals of a vacation tennis program? Are you just wanting to have some fun in the sun? Do you want competitive match play? Are you hoping to transform your game?
The first two goals are attainable at most decent tennis programs. They allow you to hit a lot of balls and get some good playing in, but to come home with a big change is tough in most settings.
Many resort programs are OK. They will often hit you a lot of balls and give you tips that may tweak your game but unlikely to transform it.
If you go to a resort program and want more, than that you might want to augment their drill programming with a private lesson. But if you do that be very clear on what you want to work on in a drill. Let the instructor now that you are willing to rebuild and not just tweak. Otherwise a pro that is only going to work for you for a week, might be what's the point of fixing your forehand and instead just try to make better the bad mechanics you have.
If you want to "transform" your game you might look more to an academy type of setting where you can spend a lot of time on court, but you will probably pay a lot too. (Saddle Brook, IMG, Smith Stearns, Van Der Meer)
Even in this setting you may need private lessons to augment/individualize to your needs. It might be wise to focus on one stroke for the whole week if you want a "transformation."
The best vacation program I ever did, I don't think exists anymore. It was Vic Braden's Program out of St. George Utah. It was a very tight program that focused on the fundamentals. They made us hit a ton of balls at the ball machine, while videoing us. Then the instructors were very similar in their approach so that feedback was consistent.
I've done a lot of drills at various programs at Hilton Head. They are good in that you hit a lot of balls, but again the instruction is more tweaking tips and not a way to change your ingrained strokes. I think a lot of coaches feel it is hard to change someones fundamentals so instead just tweak, tweak, tweak.
Most importantly, think about how much you are willing to spend. Could you spend that money at home with a good coach 1 hour a week spread out over several weeks? This might be a better way to hone your strokes. Hit with the coach once a week, focus on one thing to improve on. Work on it in between sessions with a buddy/hitting partner and hit it again with the coach. After a 1/2 dozen sessions the change is much more likely to stick than something you were told while hitting in a group at an exotic location. This really give you the ability to fix fundamental flaws in your game.
As I review what I just typed, general vacation tennis drills might be a good place to hit a lot of balls, work on tactics and strategy and maybe get a fresh set of eyes to criticize your strokes.
Whereas private lessons over time might be the best way to change/improve fundamental technique--and that might best be done at home.
