Your words hereA 592 is quite a saw. I personally really like them! But I’ve heard some guys hating on them (maybe they were Stihl guys…) because they tend to 4-stroke in the cut like no tomorrow if you don’t update your operating strategies to match the present tech the 592 has u see it’s covers. I liked every 592 I have run. Power, balance, A-1 anti vibe, easy starting, and every other positive thing you may want. But that are a different saw that maybe not everyone just falls in love with. And I’m not gonna be threatened by anyone else’s opinion…
The 390 is more an old-school saw that doesn’t disappoint either. I have one I cut my wood with. Absolutely like it. No complaints. One tip with the 390 is they need the exhaust opened significantly and if you wish to realize potential tho. They do tend to be a bit sluggish out of the box but respond well to a few well picked upgrades.
Just my humble opinion…
I must go back in this post and see the first one
The best saw on the shelf bar none. If its fourstroking it needs to be tuned via ripping (Autotune still needs this when severe altitudes change also) it wont do it itself while cross cutting. The other thing is, if you hook in and dog them hard straight up they cut on torque at lower revs, give them a slight second with less pressure and they cut at higher rpm, up to 3grand. Full chisel skip 
Exactly, because if you are thinking in anyway i dont like how the saw feels when i do this or that, its unsafe, the mind complete without niggling things at such makes for safer days
660 in my opinion ain’t close. Vibrates more, uses more fuel, unergonomic, and that damn filter has to be cleaned between refills at times. I own both, among quite a few other saws, started on 090’s in the eighties, the 592 is the nicest saw i’ve used & it never argues just stick it and pull the trigger no twisting no stalling, luv it. Skiptooth, full chisel, 32:1, 3point wcs dogs, fullwrap & duralite's
other than that its stock
Good points on user friendly. I guess I never realized how much the 66s and 660s vibrated. Until I got a 395. Then I truly felt the difference. Did not care to run 660s anymore. Ton of vibration. Getting stuck good point. And adjuster point too. Bit the outboard clutch can get you too, as my Timber falling Amigo pointed out. But for the big saws I like the outboard. Dagan my friend said he had a couple pinched, could not get chains loose to remove bars from powerheads
I've never run a 592, many 394 395s though. But would buy or run any of the three mentioned.
592 is better imo by far.Good points on user friendly. I guess I never realized how much the 66s and 660s vibrated. Until I got a 395. Then I truly felt the difference. Did not care to run 660s anymore. Ton of vibration. Getting stuck good point. And adjuster point too. Bit the outboard clutch can get you too, as my Timber falling Amigo pointed out. But for the big saws I like the outboard. Dagan my friend said he had a couple pinched, could not get chains loose to remove bars from powerheads
Said he had to bust a few chains with an Axe. I never had a problem, until he told me the story. A week later I pinched the bar on the 395, had to pull the bar it was not fun
ps I prefer the front adjuster for its simplicity with direct movement lacking extra parts and i’ve never had an issue with an outboard clutch, dunno but always felt the inboard on the stihls i ran always seemed to show up the heat??Good points on user friendly. I guess I never realized how much the 66s and 660s vibrated. Until I got a 395. Then I truly felt the difference. Did not care to run 660s anymore. Ton of vibration. Getting stuck good point. And adjuster point too. Bit the outboard clutch can get you too, as my Timber falling Amigo pointed out. But for the big saws I like the outboard. Dagan my friend said he had a couple pinched, could not get chains loose to remove bars from powerheads
Said he had to bust a few chains with an Axe. I never had a problem, until he told me the story. A week later I pinched the bar on the 395, had to pull the bar it was not fun
