Do you use hosted application services - such as QuickBooks hosting services?

I am interested in hearing some of the reasons why (or not) accounting professionals are using hosted application services in their firms and/or for working with clients, and if it's working out the way you expected. The benefit statements we hear most frequently are the ability to access any time and from anywhere; the data is backed up and protected; offers flexibility to work from home or at the office; offers disaster recovery benefits, etc. But I'm interested to know how you talk about it to your clients (if you do), and what impact this type of service has had on your relationship with your client.
J