toolgirl !!!
You have come to the right place for information. And great advice.
All VoIP is just not a mature technology, incurs licensing fees that ruin the ROI on a system, usually requires a major investment in upgrading your network(s) to meet even the basic QOS, and is unpredictable in operation unless (and not always then) you have a dedicated private data WAN between sites.
A TDM system is the "old faithful" designed for "5 9s"....99.999% up-time that works every time...sorry, no VoIP can do that. Now add some more processing power and you have the hybrid TDM system that gives you the best of both worlds without "putting all your eggs" in the VoIP basket.
You will pay either way, but do the cost factoring...the Return On Investment. The up-time vs. lost revenue for downtime. On and on and on...until your checkbook squeals. The bottom line tells it all.
Remember the last time your telephone system quit? When was the last time you had to reboot your computer? 'Nuff said!
These guys not only are giving you great technical advice, but the best project advice. The system you decide on is no better than the installation and support company. Get references. Check references. How long has this company been around? You are getting "married" to this company for many years to come. Make sure they do a demo or can take you to a customer site to demo the system that you will be using. Licensed? Insured? Professional or the droopy pants, unshaven, unkempt, and un-bathed? Computer Geek or Telecom Professional? There is a big difference.
Good luck, and let us know how this comes out.
