I have never written a bad review for anything but between the lack of quality code plus their absolute response to bug reports and asking how much longer cost me a hell of a lot more than what I paid them.
If you need a coupon component. Look someplace else, built it from one of the CCK's like K2 or even Fabrik.
In one years time, they never did come out with a workable version unless I was willing to build a site in an old version of Joomla that had security issues. Even if this was free, I would look someplace else this isn't even worth your time.