My oldest did their one week summer program years back when they were still affiliated with DU and the camps were there. She was 9 at the time. It was less expensive than it is now as well.
I'd say that she liked it, but not so much that I'd be likely to spend as much as it costs now. The few things that probably made it not super stellar were likely related to the class she took being in her passion area, which usually means that she really needs to be with older kids b/c she's very proficient in that area, and that the instructor of her class was the only instructor that summer without a college degree in the field of the class. She was really, really nice, but I'm not sure if she had background in the subject. The TA did, though.
We've moved more toward focusing on less expensive summer programs geared toward older kids b/c she does as well being in programs geared toward kids older than herself as doing programs geared for gifted kids of her age. These have been easier to get her into now that she's grade skipped and, thus, of the right grade if not the "right" age. For instance, she's doing a camp this summer geared toward kids who've completed at least two high school science courses so mostly kids finishing around 10th grade. She's 13, but in 9th and taking two science courses, so she qualifies.
I believe that she did feel like at least some of the other kids were definitely gifted, but I don't know that I'd expect a lot of HG+ kids. I could be wrong, though, b/c it has been quite a while since she went and I don't know the current demographics.