I wouldn't register at any of them at the moment. Every exchange is completely overloaded with new customers from the recent price spike and the media attention

I wouldn't register at any of them at the moment. Every exchange is completely overloaded with new customers from the recent price spike and the media attention that came with it. If you want to sign up and get verified to the point that you can send/withdraw a decent amount of money you are likely going to be waiting for weeks. Wait a bit longer and see which ones can manage and which keep having more problems.