I was certified by Dressel on the PDC side from the Barcelo Maya resort in 2000, had a great time, they are a very safe operation. As to the rental policy, you should rent your gear in the US, and check it out on a pool dive if possible, then you know you have good quality gear, and will have the same gear each dive. Another small issue is the gear they rent, the pressure gauge will probably be in BAR not PSI since they are based in Europe. If you are planning on several multiple dives per day, you should think of diving with another operation, since there dive sites are very limited. There price per dive might be more, but by the time you pay for the taxi ride into town, have you really saved any money? Since most people on this board are steering you away from Dressel they are probably right, but if you have to dive with them in a pinch, you will still have fun.