For everyone interested in this pedal let me make one thing clear: it can be used to sound (almost) exactly like SRV did on his famous song Lenny and songs like Tin Pan Alley, Riviera Paradise and Little Wing. It's supposed to be the sound of a Steel String Singer by Dumble being pushed just passed breakup when digging in. I got the best results by using it with a 60's style Stratocaster into a very clean amp set close to breakup. If that's the SRV sound your looking for this is an awesome pedal.
But, that's also the only thing it does. It's not a clean boost, it's not an overdrive of some sorts and the two knobs are only there to finetune the sound described above to suit your playing style and Amp. It's a one trick pony one could say but does that one trick very well.
If you're looking for something more versatile look elsewhere. A clean boost, like the Rockett Archer, will give you way more tonal options for example. And if you want to sound like SRV on more overdriven tunes get a Tubescreamer pedal.
Have fun!