I use a Stihl 461 at work, routinely. It is heavy, but has tons of bottom end and grunt. I would not like to use it for trail work, however, since it is heavy. With practice I can get VERY straight cuts on length, but I am familiar with the saw.
I personally have a 271 with an 18" bar, and use that for my trail work. It is a little on the heavier side, but so long as the chain is sharp it is awesome; I have cut through 3'+ diameter hemlocks (recent fall) with ease…just let the saw do the work. The large dead spire on the top part of Grannies was done by me with the 271. Took some time but no problem with the cutting. But I find, especially for smaller saws, having a sharp chain is key. I can get the 461 to cut with a duller chain by brute horsepower, but that doesn't work so well with smaller cc saws.
Without stating the obvious, I hope it goes without saying that eye and ear protection along with chaps are mandatory in this discussion. Along with steel toed boots. I was going up to do some work on the mountain I ride and in going up I ran into two hikers. They might of been bikers, but they had only their dogs. I chatted with them and mentioned the saw etc…and pointed out the chaps I had. The older man said "not everyone has the money for chaps" at which point I got a bit upset. I pointed out that if you can afford a bike of a few thousand dollars $170 chaps are cheap. To say nothing of potential cuts, a femoral bleed (in need of a pressure point) or psychogenic shock. It amazed me that someone would think the safety gear was option, as if the expense of the saw was enough. I would be very upset to find out someday a trail worker, using a saw, was hurt or died due to the lack of safety gear, even in a heat wave. When it comes to chainsaws, there is no small accident. I have had 3 incidents at work where the chaps saved what would of been a bad cut, and I never forget to use them. In fact, in my training of new hires in a saw, my mission statement is: you cannot grab the saw without eye, ear and chap protection first (I also stress gloves). After all, blood, sweat and tears is a euphanism.