I used them once and they were just ok. I just felt like I had to keep on top of my agent. We went during
free dining and we used our Disney Visa to book, and I kind of felt that if I didn't keep reminding him about the free dining that maybe he wouldn't have bothered. I don't know if that would have been the case, but it was kinda how I felt.
Most time he answered emails right away, but there were a few times when I had to email him again and he said oh, I thought I answered you. Uh, no.
He also never reminded me to make ADRs until WAY after the 180 day mark. If I waited for his reminder, I woudn't have gotten the restaurants I wanted.
Next time I'm definitely booking it myself so I can have control over everything.