3 years ago I moved my web site from shared hosting to Vps at Empire. I was really scared, because it was my first contact with Vps, and my knowledge about manging it was 0. Luckly, Empire has a great support. I must state that Dale (who I think is also owner of business) helped me so much about moving and setting up Vps. Also, later when our site got more visitors, we got help for optimizing web server and database. It was a pleasent surprise.
About availability, no we didn't have 100% uptime... thats not possible, but almost all downtimes (because of upgrades or security fixes) were announced. And thats one great thing.
Once, someone used exploit in our software to gain control of Vps, and used it to start outgoing Ddos attack. We good really fast help, and support managed to stop it and turn our Vps back to network. Usually people at host just suspend your account and let you manage it on your own, and thats not easy for someone who is proffesional jurnalist, not administrator.
If I shouuld choose hosting provider again, as for sure I would choose them again.