Talking about thickness about the blade spine and across handles I believe. Somewhere I saw a thread that showed the thickness of various Spyderco knives, and the Southard was right near the top of thickest. The blade could be thinner to increase cutting performance. Although, I don't find it too thick in my pocket, and it has sliced well for me so far.
The Southard feels just fine to me. Handle thickness is 0.530" with a 0.160" blade thickness and well-backed-up G10. Very strong knife. 204P is great blade-steel; thick-spined and will hold an edge.
My Sebenza is 0.450" and has a blade thickness (S30v) of 0.125". The blade-steel is not h-t'd very hard, for toughness, and it doesn't hold an edge particularly long. Which one of those two would I take to the woods? Not hard to answer. To clarify, I
LOVE Sebenzas for casual EDC; NOTHING better.
My CRK Umnumzaan is 0.465" thick handle with a 0.140" blade thickness. The Southard, in shape and design, reminds me of a heavier-duty Zaan and carries a similar tactical appearance in the blade. I am very fond of the Zaan; my first CRK.
THICK knives are like my BenchMade 755 MPR, which has a 2" or so blade and is 0.640" thick. This is a monster brick and I'll NEVER carry it. It was a gift or I'll throw it away. The only saving grace is the M390 blade-steel, which is strange, because BM is so stingy with their steels. I'm used to seeing 154cm or something.
A thick knife is better if it's also a longer knife, like ZT 550-560 series, although I even sold those as they were too much/too big/too heavy for my EDC.
I can carry a Southard forever and not feel that it's a big knife. I've carried this one for 2-3 weeks now, and am enjoying it. I haven't found one thing to complain about; the flipper is smooth, quick and solid and easy to put away again. I know my blade is sharp and that I won't break it unless I try to. I doubt that it will replace my Sebbie, but they might form a partnership along the way.
Hey, what does all of this mean to you? IMO, buy a Southard. I promise you will like it and carry it daily and it will serve you very well. Later, perhaps, if you have some extra bucks, ALSO pick up a Sebenza to see what all of the fuss is about. But do NOT sell the Southard. I won't.
Sonny