Hello,
I have been using their Nimar D750 housing now for at least 2 years. I was hesitant at first as well. Luckily the only real issue I ever experience was due to a main o ring failure which was my fault. I still use it to this day, but to be honest, I would not buy again. I have had to replace all the ball mounts with INON mounts since the originals didn't come with any type of friction ring (like all ball mounts) and it is extremely heavy being made of such a thick plastic. I ended up buying their vacuum LED system for peace of mind, but the quality leaves something to be desired. As far as customer service, I have emailed inquiring about the price of just the main O Ring (they only sell Kits for $40) and received no reply. Not impressed, but I guess this can be chalked up to "you get what you pay for". I will be moving onto Nauticam next.