I have used them twice with no major problems. We just recently stayed at Brisas Del Mar (Feb 15-23) and it was great villa. We did have broken beach chairs on arrival but they replaced them as soon as we called. Most of their villas are reasonably priced and they have always responded to any problems. I would use them again.
I, too, have used them 2x in the past without issue. We did have a maintenance issue at one villa (Sunrise - maybe?) and they responded quickly. I would use them again and not hesitate recommending them to a friend or family.
We used them for Stone Harbor w/no problems. They do charge the 5% service fee which I know has bothered some people in past posts; I just factor it into the price and if I'm happy with the price they get my business.