I will admit that, as a kid back in 1977, the first knife I ever bought was a Schrade large stockman. It was a beautiful knife, and I remember it costing $13. I think I ended up carrying it less than 5 times total. It felt like a big lump in my pocket. I remember walking to school and sitting in class, feeling that big uncomfortable lump. After trying out a few other knives, I ended up settling on a Buck 303 Cadet that I alternated with a Schrade "razor blade stainless" medium stockman. I felt the medium size felt right. Those two knives were my go-to choices for about 5 years.
Even though I've bought some other large stockmans, two in the past year or so, I find I never carry them. Generally, the largest traditional I'll carry is my yellow Case medium stockman in SS. It's small enough to go unnoticed, yet sizable enough to easily find in my pocket. Also, as far as SAKs go, I only carry models under 3 layers thick. For me, thickness and weight are bigger factors than length in terms of 'too big' to comfortably carry. I'm 52 now, but am still very fit and feel (and am always mistaken for) much younger. So I think in general, my choices in what I'll carry size-wise haven't changed all that much over the years.
Jim