We switched from a Merlin phone system to a Comdial phone system with all the new bells and whistles. Tri-Tel made the switch easy. The new system was installed over a weekend and was ready for Monday morning. They set up our phones and trained our users. When I have questions they answer the phone, or respond to email, promptly. We purchased a small system, only about 50 users and have always been treated as valuable customers. They really understand phones networks.