Kraken, took forever to get approved to their Tier 3 so I can buy Bitcoin on their platform. Fine, I waited, did everything they asked, submitted and resubmitted all the documentation they required.
Great, I got approved, and then I transferred 12,000 USD to them. Wonderful, I should be able to trade, right? Nope, now they ask for documents that they never said they would need, that I don't have access to (I'm away from home) — so, this is impossible and I won't be able to use their service.
Fine, just send my money back so I can use someone else. Nope, they aren't sending my money back yet almost a week later.
I post this so others are aware, to beware.