Well, I dunno. I have had to make fires on several occasions when it was really critical, and I have always gone with small stuff - usually something I could break by hand, by stomping, or by dropping a large rock. Worked every time. In my youth, I routinely cooked over open fires, employing the same techniques. The best use for a saw in my experience has been to clear out a helispot.
Or using the fire itself to do the work. Is the log too big to chop or saw? Set it in the middle of the fire and let it burn in half. Insert the 2 halves again into the fire. Its not very often that a person's only option is a huge log that can't be cut in the first place -- the smaller tinder and branches usually burn best anyway.
I've seen Mors Kochanski use a simple Mora knife to take down a wrist sized tree in less than a minute almost negating the requirement for a small saw at all. That said, I purchased a Gerber folding saw because I am not as skilled as he is.
