there are so many pedals out there that they are starting to sound the same. one of the threads i started a little while back had a link of some guy that compared 12 different overdrive/ booster pedals. most of them i couldnt even tell the difference between them. its hard to find the right one that suits "your needs" since most stores don't stock good/boutique pedals. there are no stores around me that i can drive to and just plug into a maxon od-808 or fulltone ocd to test out. as for the SD twin tube, correct me if im wrong but i think guitar center carries them if u wanna try it out.