Positive:
I am using Tele with single coils beside my Blues Junior 3, and I use this pedal to get a better and non-scratchy high gain sound. The result is very good. Blues Junior 3 owners know that if you stack overdrive pedals, then the amp sound gets very scratchy because of the amp speaker (which is actually designed for clean sounds :')
BUT, if you put Nobels after a tube screamer (guitar -> TS -> Nobels -> BJ3) that gives you a huge good hard rock sound. Strong low ends of this pedal make your bridge single coil as if it is humbucker, at the same time pedal cuts very high ends which eliminates scratchy distortion sound.
So, in my case that pedal works very good with my amp speaker to get a good high gain sound.
And the Spectrum knob is very versatile and unique to shape your sound for different genres, to be honest it is better than other pedals' "Tone" knobs. You need to see some videos which shows freq. change while rolling this knob.
Negative:
Strength is the weakness at the same time. Strong low ends are not good for neck position. Bigger version of this pedal has bass-cut feature which makes it better than mini version.
And the cheap quality knobs, I did not like them.