An ASIC outperforms a FPGA, that's why everybody stopped using FPGA's to mine BTC a long, long time ago.
The only reason I see to use an FPGA is the one that you would like to change cripto and alghoritm because one could be more profitable than the other on a specific day/period.
A specialized machine won't neìbe flexible enough but I agree that performances cannot be higher.
That's true, but it doesn't hold for POW algo's for which ASIC's have been developed. This specific
scam miner claims to outperform ASIC's for the sha256d POW algo and the scrypt POW algo, that's simply impossible.
If they would have come up with realistic numbers for ASIC resistant POW algo's, they would have had a strand of believabilety, now they do not.