I don't have any experience with the gymnastics part of Leaps & Bounds, but my kids took swimming lessons here in summer 2005, so I'll limit my review to that.
Last year my kids were ages 4 and 8, and they had never had swimming lessons before. I decided to take them to Leaps and Bounds because it was close to home. I ended up keeping them in the class for three different sessions because they enjoyed it so much!
Class size is small, around 4 kids to a teacher. The pool was deep for my 4 year old but probably chest-deep on my 8 year old. It's a circular above-ground pool. They usually have two classes going on at a time on opposite sides of the pool. They supply noodles and goggles (you can bring your own goggles if you prefer).
They have the child's progress broken down into different levels, and there are specific accomplishments they have to achieve before advancing to the next level. They give the child a certificate when they do advance.
The teachers were very nice and VERY patient (way more than I'd be!). They encouraged frightened kids but didn't force them to do anything they weren't ready to do. The smaller kids would sit on the side of the pool when they weren't receiving one-on-one instruction with the teacher. I never saw any incidents occur where the kids were unattended or fell in or anything like that. The last day of the session, parents are asked to stay and watch, but otherwise, they're asked to wait inside (in the air conditioned gym...a coke machine's inside, and they have a small selection of snacks for sale at the counter).
My kids didn't become strong swimmers but they went from being afraid to being very comfortable in the water. My 8 year old got more out of it than my 4 year old, advanced faster, but both improved a lot. I'll send them back again this year to reinforce what they learned, since we don't have a pool and they don't get to practice any other time.
And last, I'll finish with a suggestion: if you can, you should tip the instructors or give them some sort of gift at the end of the session. They do a wonderful job and I don't see how they could make enough money to pay them for what they're worth! Tell Miss Jessica that Holly and CJ sent ya!