Have you felt the cylinder temperature difference between a 660 and a 661? His theory makes perfect sense to me. We have had a lot of over heating problems with the 661 on very hot 43C degree days (107F) (we don't use them on hot days anymore)and they need complete rebuilding every 2 years, were as the 660 we bought in 05 has had its first top end rebuild done four years ago and the bottom end hasn't ever been touched. Ask any one who has made a living from a saw for the last 20 years and the will all tell you the new saws just aren't as long lasting as the ones from 20 years ago.
You've actually misunderstood what 101 was saying. He was talking about the wild temperature swings do to unheated fresh air passing through the strato passages in the piston, this is true and can cause running issues in a cold engine. This is one reason both Stihl and Husqvarna is preheating the incoming charge by routing the charge almost directly under the exhaust port.
You're referring to actual engine temperature, this is mostly cause by higher power output, on the edge tuning, restricted exhausts and poor airflow around the cylinder do to these saws getting maybe too compact. These were all issues with the 550 and 562, all of which have been addressed with the 572 IMHO, it runs nice and cool compared to the 550, 562. Oddly the 576 never had the overheating issues the 550 and 562 had, that saw was big bulky and had good airflow for cooling an.
The 661 has had numerous updates and improvements, it was a severely flawed saw until the last year or so, there is a thread here by RedBull documenting all the upgraded parts that can be retrofitted to order models. Non of this has anything to do with the fact these saws are strato in design.
Your source of information is not sound, and your interpretation is flawed, do to your lack of understanding.
Stick around awhile, lots of info here, most of it's good, like anything you have to filter out the bad. Welcome to the forum BTW.[emoji111]