Speaking of electric chainsaws, I have a Craftsman, bought new in 1975, that I run a dry chain on for cutting out termite eaten parts of beams in the old houses I work on. I don't want to throw oil in the houses, so the chains are sacrificial. It's surprising how long a chain will last in dry wood without being oiled. This one has been sharpened a number of times on other jobs, and still cuts. I only remember having to replace it once. It did do a lot of stretching to start with, but not so much later.
I ended up returning the 261 C-MQ in exchange for the less complicated 262 C-M. The dealer gave me a hard time about it even though the saw was unused. They insisted that Stihl made the swap without their knowledge and tried to convince me that the Q version was a better saw and I should keep it. After speaking with the manager of the store they eventually agreed to order the correct saw. That's when I discovered that Stihl's new 2019 order guide didn't even list the Q version. It was apparently discontinued. Hopefully I'll eventually get what I ordered but I'm disappointed with the deceit that followed this transaction whether it's due to Stihl or the dealer or both.
Glad you ended up with what you wanted. The extra weight for the Q was an odd thing, especially since the saw was intended for pro users. My money would be on both, and that would probably be the last time I used that dealer. I'm fortunate to have one I like, even though I work on the equipment myself.