What is the "average" size you will be cutting? From the sounds of what your doing, it sounds like either MS36/2 or 044/440/441 territory (staying within the Stihl line). Specifically it sounds a lot more like 362/561/6100 territory if 24"+ is the exception and by your standards the 311 is holding it's own (assuming you get rid of the 311 in the process). If you KEEP the 311 as a spare/backup saw, I would lean towards the 441/461/461 or more specifically the 372xp, 576xp or 390xp Husky, or 7910 Dolmar. I like the feel of the 461, but I haven't tried the 460 (although it's been around for awhile and is a damn tough saw). The Huskies usually handle bit better, but it depends upon your tastes as to whether or not that's a factor. How many hours will you be using it and, if more than 4-6/day, have you eaten your Wheaties? The smaller the saw you can run (while having the necessary power) the longer you can safely go, all else equal. Big saws are F-in awesome to me, but I have no desire to run one for more than about 2-3 hours... Just trying to provide some context/prospective for you. If weight isn't a concern and you like power, go 6 cubes or go home... Otherwise I'd buy the tool for which you most often need, rather most want.
One other note, if the tool is less than $2K and it's relatively fragile (trees falling on it), DON'T finance it!!!!!!!!! It's only one awe ____ away from leaving you paying for a useless piece of shop origami.
Long story short we got another huge huge huge hook up on firewood between myself and my brother in law. Were helping a guy who is logging 1000 acres total farm land. Only a few of us are involved in driving out to various locations and cutting up tops that are too crooked for his processor! Now I'm currently running an ms311 which is pulling its weight don't get me wrong! But now I am buying us a splitter as my bil has got our trailer. So I figured hey I can throw in a saw on top of the deal and get a discount. And 0% financing. I'm financing currently because it works better than dipping into my funds which are reserved for wedding 
. Anyway I am selling off my ms 311 or trading not posotive yet. We are currently working on getting ourselves atleast 3 years ahead on our firewood then selling off the excess firewood. Now my choices are ms362 (felt great in the hands) or an ms460 (test cut and it is a beast that was a blast to run). Now adding a saw only ups my payment 10-15$ so one side of me says hey go big get a 460/441 and buy a 261 next year. But I feel the smarter more reasonable part of me saying keep the 311 or get a 362 and be done.... I do feel with the amount of our future cutting and 2 current cutting spots I can justify a pro level here! Yes some of the tops we are cutting do get large in diameter over 24-36ish" (large to me anyway). The 311 has not bogged a bit and pulls great but that 362 better construction and feel in my hands was really very nice. So with all this chaos I typed out here , I was hoping to get some advice from the guys as addicted or more addicted than I!!!
