I've been using TSOHost clustered platform since July last year. It was just my luck that the day after I joined, TSO suffered a major hardware failure on their storage network (which is all openly documented on the forums) - That said, support were on hand and very responsive in both their own forums, email and the helpdesk... What kept me at TSO was the fact that they were very transparent and honest to customers about the issues, and their investigation resulted in (if i remember correctly) £xx,xxx of investment into redundancy on the platform.
I can hand on heart say that TSO's hosting is the fastest I've ever had
Aidman.