I was clearing a bunch of blown-down eastern white pine off a hiking trail. Many of them are dead due to some kind of vines that appear to strangle the tree. Kind of like kuszu down south but I don't think this is kudzu. Anyway, I found two saws are good to have because the forces on these blow downs are really weird: you might see a tree at a 45 degree angle and think you can under cut it and it'll drop, but then you under cut it and the tension from the vines just lifts the tree UP and boom, your bar is pinched. Doesn't happen a lot, but enough to warrant a second to cut the stuck one out. Plus, it's usually a mile or two back to my car if I had to go fetch the second saw.
The MMported 550XP is my friends saw and mine is stock. I was test driving his ported saw to see how the two compare. The MM saw is running 3/8ths chain and mine has .325. I'm guessing that cutting dead pine isn't much of a challenge for either saw because there wasn't a heck of a lot of difference between the two. I spied a big norway maple leaning over the trail down a bit from where I was clearing the pines. I ran out of time (and running low on fuel) so I couldn't get to it, but I'm guessing that the maple will be more of a challenge and may reveal more about the two saws.