Pros: Good power to weight ratio
Cons: Short life span, costly to repair
I have to admit I was really impressed with my MS310, right up until it burned up a bearing after 6 seasons of cutting fire wood. Turns out the crankshaft costs $243 with another $50 for new main bearings. (That's in the box, not in the saw) As someone who takes great pride in long term use and ownership of my tools it seems like you should be able to replace a couple of pieces on a saw for less than the cost of a new one.
I've owned a Stihl saw for 25 years with my first being a used 041 Farm Boss I bought from a friend in 1983. At that time I was cutting 15-20 cords a year. After 18 years of my use that saw was retired and parted out in December 2001. That's when I bought my MS310, a step up from the current "Farm Boss". By then I was only cutting my personal store of firewood and brush clearing around the farm. Seven years later I'm faced with buying another saw or spending more to repair the saw than I paid for it originally.
Stihl's response was that the warranty is 12 months so I got my moneys worth out of it. They suggested going up to the professional grade saw rather than the "Mid-Range User series" but the warranty is still only one cutting season so I'll be doing some shopping before my next purchase.