I'm an instructor that works in a resort based environment and I really like it. You'll probably get a mixture of reviews but in my experience, I think the results of e-learning, especially in kids is generally better.
It does depend on the student - how motivated are they to learn etc but I find that if they want to do well then the e-learning does facilitate this.
It also depend on how/where the course is being conducted. If done back home then some centres run some really good programs where the theory is scheduled over a period of weeks and the student gets a solid learning experience.
If done on vacation then typically, the theory section of the course is allocated a day in the classroom. Both work, but if the student has issues with anything and needs more time on a subject then there is generally less wiggle room on the resort based course.
The other advantage is that often kids don't like spending their vacation sat in a classroom, especially while the rest of the family are out doing something fun.