MS261 is 4.0 bhp, 10.8 lbs, $560I second that. I thought it earlier, but didn't feel like arguing. No suffix anything. Not good for reliability. Also, Why "farm boss"? I've heard them said to be a cool name on a saw that has more than its share of problems. That's why I keep a MS250 with a standard bar (catalog says 18", it's not, it's more like 16.5), and have a MS261 with a 20 inch bar. This works for me. I used to have a twin cylinder Echo also, but it's gone and what I have now does what I need.
Reliably.
MS271 is 3.74 bhp, 12.3 lbs, Farm Boss, $409
1.5 lbs is a lot of weight if used all day. The side chain adjustors on a Stihl larger saws is nice to not loosen the bar to adjust.