Bitstamp likes to hold onto your FIAT deposits for days / weeks on end without any explanation.
If you send them a support ticked asking if everything is OK to deposit you can expect a reply within one hour.
If you've actually sent a deposit and you ask them where the funds are be lucky if you get a reply within a week.
Kraken: Kraken processes deposits very quickly, they get credited the next day. Their website keeps crashing with error 520 and 500 making it almost impossible to use.
Bitstamp: Very quick to reply and encourage you to deposit funds. Very slow to actually credit you those funds. Beware.
CEX.io: Also very slow to credit bank wire deposits. Have never tried a bank wire withdrawal. Card withdraw was OK ( Till now ) Same silent treatment given by Bitstamp when asking about a deposit. Read the official thread here on bitcointalk, place looks like a nightmare to deal with.