In the case of the Colt SAA, and its faithfully-designed copies, I do like the 7.5” barrel length, once it is in my hands. The balance and overall feel is wonderful. If I have to carry it, in a vertically-oriented belt holster, when concealment is necessary, and/or while being seated some of the time, 5.5” is a better barrel length, unless I want to be hanging by my belt-holster rig. A chest rig or shoulder holster would be best, for me to carry a 7.5” SAA-pattern, in circumstances which would include being seated. Thus far, my chest holsters do not include one which will accommodate anything longer than a 6.5” sixgun, so, I do not yet normally tote my 7.5” USFA Single Action in it, because I would rather not bang metal against metal while entering/exiting my truck.
Ruger Blackhawks and Vaqueros seem to balance differently, for me, than faithful SAA copies, so, I am not so sure that I would like these Rugers to be longer-barreled. My 5.5” Bisley Blackhawk, .45 Colt, with a .45 ACP being my point of reference, I am not so sure I would want it to have a 7.5” barrel. I almost never see 7.5” Vaqueros, so, have not handled one. With less metal in the top strap, and the rest of the frame, than in the Blackhawks, I might like a 7.5” New Vaquero.