My cheapy compression tester has always read 15-20 psi lower than my Lysle tester. I just tested my 394 and it had 150 psi on the cheap tester, and 30 psi on the Lysle. Yep, looks like my Lysle has gone kaput over the winter (schrader valves are good and air hose is good and clean). My 394 runs great and has noticeably more nuttage than my either of my 288s. I'm not worried about it. I took the muffler off last summer to port the muff and the piston/ring on the exhaust side looked great. Cylinder looks good too from what I can see through the spark plug hole with my good 600 lumen flashlight. If it were my saw, I wouldn't rebuild it just because of a somewhat low compression reading. If it runs good then let it keep running good. The 395 cylinder should give it a bit more power, but from what I've read, that isn't really the case. The difference between a healthy 394 and a healthy 395 isn't noticeable.
Unless the saw has had a lot of use, I doubt the ring is worn to the point of being worn out, assuming the air filter has been doing its job. I've only had two cases of a severely worn OEM ring in my huskies. One a weedwhacker that I used A BUNCH for 10 years, the other a 55 rancher that was used a lot before my dad used it for some years. If you pull the muffler and the piston skirt and ring look good, it's probably ok. If you're just looking for a reason to tear into it, then go for it. I've also found that the carb tune can make a big difference in power output. I've set saws a bit rich where they would 4 stroke a tiny bit in a light cut just to be extra safe right after a new piston/cylinder. If tuned to the point of no 4 stroking in the cut they gain a good bit of power. If I turn the high side screw in about another 1/5 to 1/3 turn beyond that, it'll still slightly 4 stroke at WOT out of the cut but also pick up a very good bit of power over the "just not 4 stroking in the cut" setting. Maybe it's a tiny bit lean that way, but I don't think so. It may not leave much room for error in fuel mix or a crankcase leak, but that's where the engine really wants it set. In short, if it has the power of an 80cc saw, it may be only 1/2 of a high side screw turn away from getting to its full potential. If the power falls flat at WOT in a heavy cut, it's too lean.
I can say that my 395 (which should be very similar compression) is almost impossible to start without the decomp. I mean I can start it if I put it passed TDC and yank as hard as I can but I don't like too it has a new oem top end installed just last year so she is fresh 
