Yeah I toss a 20" in the skidder, but all it does is bump knots and occasionally knaws on a stump or two. The rest of the time its 32" 36" or a 42" for all my falling needs (mostly 32's). Partly cause putting a 20" bar on a 76cc saw is a great way to over rev, and because if I had to carry a bar for every tree then wouldn't have enough energy to pound any wedges.
I think you folks with the short bars and cutting from both sides are missing some details when compared to production falling, Most of us get paid by how much wood we put on the ground in a day. The more we can dump the more we get paid, even me the lowly gypo... if I can put an extra half or full load on the ground then I can be done and move on to the next, and basically get paid double time. After all I'm the boss I don't get paid unless there is wood going to the mill, the more that goes to the mill the more I make.
Running around and hacking at it from all sides just takes time, get a long bar try it out, then start telling me how much a short bar is better. Sure a long bar takes longer to go the same lateral distance as a short bar, but it only has to do it once, and you don't have to walk around the tree, not to mention much of what is cut out here you just can't walk around the tree. I've cut some that had 8' of stump on one side and only 6" on the other, I've seen others where the bottom side of the stump was 30-40' from the cut, and the cut was done technically at ground level.
Not to mention limbing with a short bar is just murder on your back. Unless your lucky enough to be standing on the ground all day, which I for one am not, hence the shoes with the purdy steel spikes in em.