great topic as I am in the process of moving host. I was with Registerfly.com. My site was constantly down and the service was appaling. I was so angry that I requested to cancel my hosting and get all my money refunded. They did exactly that and now I am in the air and the site is down. Of course I signed up with a new host immediately, but it still takes another day or so and the site is still down. Very annoying. I admit it was a mistake to cancel everything with Registerfly before I had signed up with another host but the site was down with them for 3 days before they even attempted to fix the problem.
What a useless company.