NOT OMT. Their support stinks, the people are rude and it's always "your fault" their software isn't working. I have a client on it, it's clunky. Each task, such as logs, voice tracking or production requires launching a separate application. Very counter-intuitive.
I recommend NexGen as well. I've heard good things about Wide Orbit but have never used or installed it, so I can't comment on it.
If you have a good engineer to set it up properly, Enco can run well. NexGen is a bit more user friendly in the setup department. Enco support is also very good, as is RCS. For the cost of these things, the support people should treat me like gold (like Enco and RCS) and not an idiot.