testtrack pro is used pretty extensively in large companies as well as small ones. it is highly configurable, easy to use, continuous updates available for customers, and inexpensive compared to other tools on the market (not taking open source into consideration... different ball game)! what would you like to know about testtrack pro?
Don't buy it if you want to do any type of major database configuration or field control. At about $1000 a license there are better options out there. It is quick and easy to establish an initial database but I would never use it for any company that wants total control of the database or anything over their initial out of the box experience. It does not provide for easy updating either. Some of the features in the application work but they don't work well enough or do enough to meet an administrators needs.
Is your company cash poor? Do you have a demo? You can see the initial setup. You can buy it if you are happy with the initial look and feel and don't want to update it much. There are probably better options out there.