I've used them in the past without issue but I'm not sure id do it again. That's not because they're dodgy but their kyc questions are ridiculously invasive and they rescind verification and ask for more if you go over unknown limits.
I'm buggered if I'm getting tied up in their secret policies.
Their KYC questions are indeed quite invasive.
However, in my experience you can get away with rather vague and ambiguous
answers and still get through the verification.
It´s probable that they do not really care for the details they ask for, but rather
want to have plausible deniability in the case of government investigations
into a Bitstamp client.
All in all, Bitstamp is the best of all exchanges in my opinion. The big downside is
that they don´t offer Margin trading.