For what its worth I've got a stihl, 361,460,660 and have had in the past poulan, homelights, lombards and some other assorted junk saws. Before you consider any saw from anyone, find out if you've got service in your area thats any good, thats why I went stihls years back, service and parts. I run anywhere from 16, 20, 24,25. and 36 inch bars on mine and switch from 3/8's to 404 all the time between saws. I'd personally never run anything bigger than a 20 inch on my 361 or 25 inch on my 460 but thats just me. If I had to buy only one it would be a 460, its the best all around saw I have for power and weight, for liimbing the 361 is fine, for anything bigger we all take the 460 and I usually get the 660. I'm not sure what your going to do with them but I'd go for any "pro" saw stihl makes over the regualr saws. As for amount of usage I put on my saws, I run between 100-200 feet of chain per year and my 361 and 660 are about 7 years old now the 460 is two years old, so I don't know how that stacks up for usage compared to anyone else or not, low, high or medium. I've had to replace on muffler on the 361 and several bars, usually from getting bent or twisted, operator inflicted, but thats life. An oiler or two on the 660 and otherwise nothing but tune ups and chain and gas/oil. Pretty happy compared to anything else I've owned over the years.
The 460 is a balanced saw with a 25 inch bar on it and has some guts and power to cut fast, even bigger stuff, the 361 is pretty small for much of anything big, my dealer handed my a saw either a 440 or 441 to try out and make a few cuts in a log he has out back and I handed it back to him, I didn't like it at all, too heavy for very little extra power and not as balanced of saw, maybe but thats a long time ago now, I did demo a 460 from him for two weeks also a dolmar saw the same size, but decided on the 460 for interchangabiltiy of bars and drivers. That size of saw is ideal if I needed only one saw, my whole family commented on that when we were trying it out, actually if we have bought that first I don't think we'd have a 361 at all, just a 460 and 660 saws, but I like power, over lighter weight, I want to hold the throttle and see things cut fast and not bog down, but again thats me.