We've had several trampoline threads over the last few years, so if you don't get as much response on this one as you'd like, try searching for them. From what I remember, the reviews are quite mixed (what a surprise!). Some moms won't let their kids near trampolines and some of us own them and enjoy jumping on them with our kids.
My girls really enjoy ours. We have the giant net around it so that can't get near the springs, which are covered. My kids don't do flips, they just jump or do somersaults from a standing position. Pediatricians hate trampolines almost as much as scooters because of the number of injuries they see.