I have an account with Kraken, though I have made no buy/sell transaction as yet. only done so via localbitcoins, which went well and fast.
Will come back to update this post when When I make a transaction, but the one thing that drew me to them, is the fact that this page says they are legally compliant:
https://en.bitcoin.it/wiki/Buying_bitcoins (search for Kraaken)
And while i haven't been able to find exactly what law they comply with, i believe the fact that the company is US based, must mean it is US laws. Maybe someone else can comment on this?