Am taking QuickBooks hosting services from Ace from almost 1 year now. There were some server downtime issues initially. Unresolved issues for many days were also a matter of concern for my company. I tried to get in touch with the technical staff and was assured of better performance but nothing much changed.
However, now they seem to have improved in those terms. Last week they delivered our 3 servers within 45 minutes.
I would still suggest this company for hosting purpose because they still have something better than the others. Their customer service has improved a lot and is professional in handling queries. The security of your private data is dealt with excellence. Login issues are very minimal and the remote access of applications works fine. There is nothing much that is alarming.