I have used them with mixed results. This month I got 4 fish and 1 coral. Coral is doing fantastic. 3 of the 4 fish are alive. 2 I don't see much. 4th one, a small court jester goby might be alive in the tank somewhere as I have a ton of places it could be. At first I had 2 fish out of 4 out, then 1 wrasse disappeared and I was bummed that 1 other wrasse seemed it. Then I saw the royal gramma a week later and a couple days later, saw the other wrasse living in a paly hill. So this last time was a good experience.
I have had losses and they 've always credited my account. I have trouble with frozen food. When it arrives thawed I get credit, so I've always had good service when I've had orders that didn't make it. I don't think they are any worse than any other on line service.