Micnac – Here is my take on the listed products :
Quintum – the A200 is crap in many differnt areas. Please dont even go near it. If you have a problem their solution is to replace the unit.
Qtelnet – This a nice unit. Fairly easy to set up and the quality is excellent. You can expand the Qtelnet gear to 100 units without the need of a gatekeeper, beyond that you can use a soft switch or gatekeeper. I like that when their are firmware upgrades they can all done remotely through an FTP site. They recommend a retail price of $575.00 but I have seen them for less online. Best bang for the buck my opinion
Mediatrix – Well to be honest I never got through the set up of one of these units. What a nightmare! To set up the units it comes with this flash reprogrammer and no web page interfaces. I gave up and returned the unit. They are cheap mind you but you get for what you pay for.
There is Multitch as well but they are way overpriced. You are better of with a Qtelnet fxo.
Drop me a line if you have any questions at firstname.lastname@example.org