I prefer the MS 171 over the MS 170. I like the 171's twist-lock caps, side-mount chain adjuster, adjustable carburetor and larger bar oil and fuel tanks. Though the 171 weighs a pound more than the 170, spending the additional $20 to get the MS 171 is worth it. I really dislike the front mount chain adjuster.
That being said, where I work, we sell a lot of MS 170s to people wanting to use them for limbing or keeping them on their side-by-side if they come across a tree which has fallen across their path. Definitely a handy little saw!
