I've been with zFast for rather a long time now, around 2 years and there's never been anything they haven't helped me with. They offer brilliant after-sales support and really cheap prices. Honestly they have served me well with extremely minimal downtime and issues. They are fantastic for first time users and offer great support and aren't afraid to get stuck in and help even the most experienced users.
zFast have always been there for all my hosting needs and I'm very glad i found them, great customer service, great prices and one very fast and reliable network.