Having used Smart now since May 2015 I have to say that I'm impressed. My website has been without problem and faster now then it ever was with my old provider (Heart)
The technical team are friendly and helpful at all hours and having phone support really does make a big difference when you need fast support.
I recently had a few issues with a WordPress update which the team were fast to help with, in the end they restored my website from backup and did so in a speedy manner.
Very good service from a UK company.