This is the middle-ground saw we chose from Silky. Not too big to go into your day pack, not too small to get out-classed by a 10" tree. It's built like a non-folding saw, but allows you to tuck it away like a POCKETBOY.
From Silky's site:
The Ultra Accel 240 mm is a saw with the folding action needed for portability, but with a sturdy aluminum chassis and large teeth to give it the cutting power and stability of a fixed-blade saw. The Japanese steel blade features impulse-hardened large teeth that make slicing through a limb quick and easy.