Two weeks after switching to GoDaddy's Microsoft email service, that is what they call their Hosted Exchange sevice which I think confuses people, I am very satisfied with the service. The iPhone and AT&T networks is working well with push email with messages arriving almost simultaneously with those in Outlook 2007.
My friends and colleagues are now starting to switch. The only issues so far have been:
1. 4smartphone required an entry in the hosts file to make Exchange's autodiscover feature work. That entry must be deleted.
2. We found one PC which is unable to find or connect to GoDaddy's Exchange server and are currently thinking that is PC related since we have been able to successfully create profiles for the same account on 2 other PCs. I will update when we find the issue.
3. Calendar items with invitees created under the 4smartphone account sometimes are not modifiable. Exchange tells you that you are not the owner. Updating your organizer email address in the item solves the problem.
In conclusion, the switch has been seamless and it was worth it from cost standpoint and better integration with my domain name DNS.