Yea I have.
I ordered my dwarf neon rainbowfish from them.
I ordered 12 in total, 8 where healthy but the other 4 seemed to have some kind of internal bacterial infection and died within days of getting them. They said they would refund me for the 4 that died but they never did.
To be honest tho im not suprised I had loses as the water was cold when they arrived dispite the heat pack.
They are also pretty expensive and to be honest I dont think I would use them again. Only advantage is the great number of species they carry.
Imo If I was you I wouldnt bother. Call your local lfs and ask them to get in whatever fish your after.