"a 10' 10wt. single hand rod?" Now that would be a beast!!!
To add a bit more to this fine discussion, consider. I used three identical rod models for a purpose for the minute you start comparing spey to single, to switch, etc - all goes out the window. Even with single hand rods I'd group them into at least four groups, full flex, mid flex, tip flex and and near no flex!
Test rods in the same grouping since flex, in effect, shortens the rod. One of my favorite big game rods is the nine ft BL5 a Winston offering with loads of tip flex giving it the characteristics of my old 8'9 RPLX, a much stiffer rod.