Be careful.
After finally getting a verification to go through (took a month), I've tried the instant buy feature over 20 times. Each time, the transaction is instantly cancelled as being "too high risk". We're talking purchases of .25 btc...
The feature that used to work - 5 day wait - is no longer available. They apologize in the error message and ask me not to give up but try again in a few days/weeks... what b.s.
no help from support staff either...
They sure are having a lot of growing pains for a company which received $6 million in funding.