We have been using KVS now for some time and we haven't looked back since. Our experience has been nothing but great since day one.
KVS meets all the modern requirements in today's dynamic market. It will suit any business models as new versions are released frequently with new features added all the time.
On top of this, the script is amazingly flexible and lets you reconfigure it as needed.
KVS support is timely and extremely helpful to say the least. They seem to be there for every issue no matter how little or large it may be.
The KVS tube script was exactly what our team has been looking for. The script has unlimited possibilities which can satisfy even the tech people which are really hard to please.
Besides that, the script is perfectly stable. We have more than 500K unique visitors on one of our tube sites and we never had any problems.
There are a lot of features, but the script is easy to use and the developers offer fast and efficient support (install and migration).