My thoughts, 7 sleeper nailed it. I grew up on a farm heating with wood, and we never had any "Pro" grade saws...my dad had a ProMac 650 that we cut EVERYTHING with, from felling the tree to 2" stuffand smaller, he'd cut, my siblings and I carried it to the truck. We were always falling behind, and that saw ran a 16" bar and weighed over 18lbs. I grew up running 16" saws, I think they're perfect for *most* fire wood duties.
I just went through my old Mac 110, stuck a 14" bar on it, and it shakes like an epileptic on a vibrating hotel bed, but you know what? It cuts firewood!
I personally couldn't see walking around in the trees all day, cutting up stuff that has already fallen (there's a LOT of it all over here in SD!) with a 20+" bar...I ordered myself a 5100s with an 18" bar, but I *might* go to a 20", just because I'm getting set up as a dealer (I hope) but honestly, if I was going to buy one of the new Dolmars, for what I call firewood, I'd be looking real hard at the new 420, around $300 bucks, 16" bar, light, smooth, easy to cut 3" branches with as well as fell the smaller trees. I dropped an old tree on Sunday with my old 16" Craftsman, the tree was about 20" at the base, and I didn't cut through it fast enough to send a video to youtube, but the tree is in little bitty pieces now!
That said, I can only run these saws about 45 minutes before the vibration makes my hands numb, which is why hopefully by the end of the week I'll have a shiny new toy! :greenchainsaw:
Like I said, just my thoughts... I consider "firewood" wood that I can cut and stick in the fire, not necessarily wood that all needs to be cured/split/stacked and burned next year. I cut lots of 2" stuff that is dead that I see laying around, it burns well and starts easy!