Did anyone send their kid(s) to the Day or Overnight camps at Ripkin's Youth Academy in Maryland and how good are they really?

Ripken camps are good. They are designed to teach kids correct fundamentals. Most kids are subjected to coaches who volunteer, some are good and some are not. Even in high school you can end up with a baseball coach who just happens to be the only guy free during the season and actually an assistant JV football coach. But to a kid, they hear that advice forever. In a Ripken camp they will hear the correct advice and get the correct fundamentals training.
After leaving a minor league farm system, I was roped into coaching high school (17-18 yrs) kids in a highly competitve traveling league (supposedly all made up of kids preparing to play college or MLB drafts) and was shocked at how little the kids knew about baseball. After 3 years I decided to go back in time and started working with 8-12 year olds and teaching the same fundamentals that the 17 year olds didn't have. By the time those kids reached the same advanced leagues they were dominate on their teams, they understood the game better and played smarter than any other players of their age. Even if they didn't have as much raw talent they were better players that you would prefer to have on your team.

Ripken camp will do the same for your child. It may not make them the next Pujols but they will leave camp with fundamentals that will keep developing years after you sent them. It's one of the best investments you can make for someone who enjoys baseball.

As a side note - my parents started me at age 5 with Mickey Owen baseball school. And to this day I still remember several outfield skills I learned at 5 that I have had to teach 17 year olds.

My cousin went to a Ripken Camp and found the experience worth while. They work with you on the basics of baseball and are very good at teaching you the fundamentals.