I have been using it for about 3 years now. Cheap, wonderfull, works great.
However, it restricts you in quite a few things. You can not use all httaccess function things or whatever, I have had problems with that, and also you can not configure cron, or anything close to that. Only the basic stuff.
Also, they shut down your website if you do not protect yourself well against spammers.
However, their support is great, and I have never had any downtime or long loading times! Currently I am managing inactive websites
www.lolsoft.com and
www.bv-luw.nl, two drupal websites running on servers from one.com