I haven't seen this mentioned yet...but it is true that the 16 preset amp models can not be overwritten, however the models are all setup with autoFx which means that gain, bass, mid, treble, chorus, delay, and even channel volume are all pre-set based on what Line6 thought sounded good for each amp model. This can be turned off by going to setup>AutoFX>Disabled. Now whenever you turn the amp model knob it does not automatically set the parameters, rather it uses which ever position the knobs are at on the amp. So if you leave the channel volume at noon, you can turn the amp model knob and have consistent volume for each one. Hope this helps!