I'm a newb, home-gamer.... dad has had his 034 for 30yrs running anything from Stihl (white or orangle bottles), Echo, to Arnold I think (something from the local Sears). 50:1 with 87 or 89 E10 (only E10 in CT). He doesn't cut that much, but enough to feed an insert to offset some of the heating bill.
Definitely not representative of every user, but for the average homeowner use (occasional storm cleanup, couple cords a year) the saw still rocks. I actually plan on "refreshing it up" for him. Mostly rubber bits and some consumables... we'll see how the piston/rings look.
Anyway, I've been burning Stihl ultra (extra warranty for trimmer & blower I bought) at ~45:1 for the first few 4-5 tanks in my saw. Stihl ultra is $13-16 locally for a 2.6oz 6pk. Echo blend 16oz is $9 at HD. I don't want to have various mixes, but want to protect the 4-mix engines from deposits.... I'm planning to try out Saber Pro, $13 currently (currently free shipping) for 32 oz. At 50:1, I think it should be sufficient for the blower, trimmer and saws.