tone bender differences

[gdmart]

im looking over the layout on the ggg toneburner and the ggg 3 knob toneburner,and Id like to use the tightness switch on the 3 knob toneburner is that ok? Will I need to adjust other values?.I notice a 100uf on c3 on the tone burner and a 22uf on the three knob seems like quite a difference what will that cap do for tone. Im wondering which to use.?Also there is no r18 on the tone burner, c9 is in a similiar posistion and it is a 2.2nf ,again why the difference and what do they do in the curcuitand lastly what does the r19 string pot do??  thanks