I bought this unit to replace my IPS33b, which is still going, but I needed some fresh sounds. I found alot of the preset patches were somewhat erratic regarding output volume, and have only found a few that I am using, relatively unmodified. One of the tricky parts is that there are menus of parameters within other menus of parameters. Also, to modify some parameters, you need to locate the proper parameter and then adjust. Some are not where you would expect them to be.
Many effects have their own seperate mixers, which affects how the effects work with each other.
Suffice it to say that this is a fairly complex unit to get used to at first. But if you spend the time tweaking, you will be rewarded with some very cool, usable sounds that don't sound like everybody else. I play modified Fender strats, with bridge humbuckers and Floyd Rose Trems. I don't use the internal distortion, which sounds aweful to me. Not lexicon or Eventide, but still very good.