I've been cutting the last year and a half with my Dolmar 510 and either semi or full chisel, and as a general use saw we get along fine...but it boggs down a bit when I bury the 18" bar in tough dead oak, which we cut a fair amount of...so...enter a new 7900 with a 20" bar. I figure I can always run and get a bigger bar and have plenty of saw to pull it around when the need arises, but as a firewood saw, 20" should be adequate 99% of the time. A few pics: