I caught the 5100 virus here on AS. I asked my dealer to sell me the saw with 3/8 - 18". As delivered, it had that odd rounded-raker chain -is that safety chain? The dealer traded me even for Oregon 72 chain. I hand-file and avoid dirt any way I can. The saw cuts great even though just a couple of tanks of fuel. It also idles fine, guess I'm lucky. A bit easy to flood when starting, but starts good with two pulls on full choke then ease off and starts on the third. Seems good at the warm restart.
Another thing I like is that the fuel and oil tanks seem to not taper up toward the fill cap. On both my other saws, as you fill fluids at a steady rate, just as you get near the top the tank narrows or something and you're apt to spill over. That seemed better on this 5100.
I don't have another modern saw to compare this one to, but for smoothness in the cut, great anti-vibe, nice compact size and light weight, and good power I'm going to like this one a lot. I don't have any trouble drop-starting either as some have mentioned - doesn't need decompressor. Maybe I just got used to my Jonsereds 80. Both the 80 and my Husky 41 also jerk the starter rope just as they stop turning after shut-off. I got so I'd pull a couple of inches of rope out at shut-off to save the rope, on both other saws. The 5100 doesn't do that. Very happy with the new saw. A big thank you to the other fans!
Jim