It does not look like he concerns very much about the profitability of his exchange service. Most rates are 0 and he also encourage other people to start their own exchange services.
That's absolutely not the experience I had. My complains are: 10 days between my IBAN payment and the money showing on my account (And they can't even blame the bank because they acknowledged receiving the money after 5 days), an insane fee to enter the system, a fee for each transaction proposed (even if canceled afterward) (*) and a fee for each transaction finally done.
And of course this all happened to me the day before the DDOS so, when I heard about the DDOS, I bought all BTC I could (at a very bad rate) to quit btcex, figuring that nobody will do business with them anymore. I still have to recover from this lost.
I must add, to be perfectly fair, that they replied to my mails (even if it takes some times) and that it looks like they operate that "honestly". Anyway, if it is proven that they are involved in the DDOS against mtgox and bitmarket, it means that they are ready to do illegal stuffs, which should make anybody highly uncomfortable about using their services.
(*) the fee for each transaction proposed was removed after I left btcex because it was really insane. I was trying to understand their UI, adding proposals and canceling them when I realized that, each time, I was loosing money.