I was having so much trouble with my previous hosting management company that I dropped them and went with Sprintserve.
The previous company had issues with moving my server from HSphere to a Cpanel control panel - it took them 2 full days to 'complete' the migration. No follow ups, no work on their part to fix up anything that was not working.
To their 'credit', they did advertise that they have no experience with Hsphere.
I was so fed up with their lack of communication (no phone, no IM, only tickets which one technician ever replied...if he were working) and lack of effort that I cancelled that service and found Sprintserve.
Sprintserve did the job in a matter of hours. They followed up and made sure my x-cart and whole shop worked perfectly. It would have been much faster had my internet not died, and had I been able to keep up with SprintServe's request of information required from me.
Highly knowledgeable, fast and responsive - I recommend them!