The in store always looks a mess, fish are almost always sick from the in store.
Online is a different story.
I have used their online store, I got a few clams from them, all of which have died. That isn't to say it was their quality though. I dropped my derasa trying to move her to another tank, she took a bad fall back inside the tank with the rock she was attached. She was super healthy for about 5 months that i had her.
My crocea lasted about a year, bored itself into its rock, and something in the tank was bothering it. Maybe the blenny that kept resting on it or my annoying shrimp, either way she stood closed for a few days and died one day. I still have 4 big maximas not from petco in the tank so it definitely wasn't a water issue.
I have also bought fish from them online in the past. My mistake was buying things when on sale and rushing them into an already sick tank. (rookie moves). Besides my mistakes the fish looked super healthy until they got sick.
Anyway, If you are within their guarantee period and you send them a photo they will give you your money back in full. If you add a little extra complaining they even give you some rewards towards your next purchase.
All in all, if you are experienced and QT what you get and acclimate properly you can get some nice stuff from them and if you wait for a sale you can get them pretty decently prices. 14 day guarantee is not bad compared to a lot of these 1 or 2 hours places that are priced higher.
