I have heard of them before from the NXT community and of the NXT wallet they provide. I have not read bad things about them at that community but it is never a good idea to not be in control of your private keys. So I would not use.
This is how I came to know regarding this wallet. Due to some issues with Bittrex and Hitbtc, I tried to use this wallet to buy some NXT due to that airdrop thing. But everything fell apart.