I see the post's about your tank vent, I've heard this is an issue with the 395 from a few locals, but I have zero hard evidence on that fact besides heresay, so don't quote me on that.
My 394 has been pretty decent, and I have not babied it.
a massive step up from a 455, lol.
Interestingly, when I bought my 394 with a 30+ inch bar my only other working saw was a top handle echo CS3400... I made a huge leap I wasn't quite ready for, lol.
It actually scared me enough at 14 yo to make it spend the next ~ 6 years in a box in my closet partially disassembled while 50+ other saws of various size, make, and model came and went!!
my take on break in;
I personally try to limit how much idling any 2-stroke machine does in its fist few tanks, and also limit any high speed revving outside the wood.
Beyond that, I just pick out a very sharp chain & go to town on the woodpile
This is what my grandpa taught me, he cut **** loads of fire wood both to sell and to heat his place, and I still have a couple of his more used up saws that are 50 years old, and 35 years old respectively.
both run & are on the original cylinder with plenty of compression.... too heavy to use regularly, and along with having sentimental value they mostly sit on a shelf in the dinning room now.
me and a couple helpers cut & process on average 60-90 tons of trash logs into firewood a week for a side busness in the fall. Just ended this year... I used 93 gallons with my 661 alone in the 116 days we cut this season!!
Some of my favorite work saws have 2500 documented hours, cutting & idling, & still perform very nicely on the original cylinder... My approach seems to be working as far as I'm concerned.