Personally I like this plugin. I tested it with a tone and analyzer so I could understand its sweet spots and limits. It can be pretty subtle or a very agressive, like a real tube. With everything at minimum setting, it still produces some subtle harmonics, ideal for the master buss if the mix needs to sound a little more round and full. With higher settings I got a saturation similar to tube preamps and in mode 2 I added some more agressive distortion to an electric bass. Overall it is a useful tool for me and it is free so thank you Voxengo.