I have a friend who went to the Club Med Punta Cana last summer and loved it. Her kids were 8, 4 and 1 at the time -- she said the only issue was that the baby was too young for the kids' programs, but the 2 older kids had a blast at them. I was looking seriously at this for our spring break this year (until I found out we had enough starwood points to get several free nights at the Westin on Grand Bahama). I think an all-inclusive would be perfect with kids the age of yours as it would give everybody some freedom to do what they want -- your older kids could go get a snack, etc. without constantly having to ask for money. I'm sure you and DH would enjoy having a little time to yourselves, too. The kids program must be pretty good if my friend's daughter participated -- I had her in preschool one year, and she can be a bit tentative in a new situations but this was apparently not a problem.
One thing I did find in online reviews it that (particularly during the late summer) the majority of the guests at the resort are European (esp. French) and the primary language spoken is French. Also, there were some references to women being topless on the beach. You might want to think about whether those things would bother you. IM (unsolicited) O, the exposure to another language/culture is always good, and as far as the beach goes, I trust my DH and my 9 yo DS is still at the age where he say "eeewww gross!" It wouldn't stop us from visiting there, but if it would be an issue for you you might want to look at a resort that has more of a primarily American clientele.
It doesn't matter what you think, just that you do.