I believe mine is a 300. Unbelievable saw. I'm an old mechanic and appreciate good tools. I'll use my Silky until it's no longer useful and then buy another one. I bought mine last fall and plan on buying another one for my soon when we do more hinge cutting next fall.
Where they really excel is in the canopy. Zubat is 9oz, chainsaw is 9+ pounds. So even if you have to pull a few times to get through a limb it's still less overall work than lifting the saw over your head. Chainsaw is going to be faster, but not always easier, and certainly not always as safe. I've yet to find anyone who's had a pruning saw kick back in their face or cut their leg open to the point of needing stitches. ;)
What you hinging guys really need is the hydraulic backpack pruning chainsaw. Those things will eat your ms170 for a snack. :D