It is pretty subjective but I largely favor the Stretch2 for many reasons. I will always take thinner stock over thicker, I prefer a backlock to a ti frame lock, I prefer a FFG to a hollow grind, I prefer a satin blade over a stonewashed blade, I prefer choils over the added edge length you get without one, I prefer an easy to operate Spydie hole to a flipper, I prefer washers over bearings, I prefer a symetrical knife over one with two different scale thicknesses and I don't favor internal stop pins. I do love CTS204P but ZDP is a steel I also enjoy. I own both and carry my Stretch2 all the time and never carry my Southard. The Southard is super nice, with a great steel and the fit and finish is spectacular. It just isn't a good fit for me. I don't mean to put the Southard down and would never try to talk someone out of buying one. I hope I highlighted some of the key differences to help you decide which is right for you.