Update;
bought the Husqvarna in part because of the 4 year warranty vs 2 year on the stihl.
I WAS originally leaning stihl because of a few small things like the choke on the husky being a flimsy looking plastic pull tab, and the fuel/oil fill caps
made to work with the scrench. my FIL has a few jonsered like that and the plastic where the scrench fits is broken on all of them and they are a bitch to get out to fill.
HOWEVER, on the newest models of husky they have a stronger choke lever and a flipper on the fill caps so they are tool free.
that plus the warranty closed the deal for me.
so I ended up buying the Rancher 455 with autotune.
I have since cut about 5 cords of mostly red oak and I am pretty happy with it! the auto tune was a bit off at first while it collected data.
in the directions it says you need to initially run the saw at full RPM under load (cutting) for 3-5 minutes....damn saw cut too well to do that.
I tried slicing away at a big oak for a minute or two to " program it"....but apparently that wasn't good enough as occasionally when I would get down with a cut
the saw would die, very annoying.
then came across a large "Y" section of oak that I needed to slice up. cut about 2 feet through the middle of was is basically a huge knot and that seemed to do the trick.
has been running perfectly since then.
I would also mention after all this cutting the air filter still looks like new, so the airflow precleaner deal seems to work quite well!
fuel economy seems to be good. cut all this plus two more trees in another area on one tank.