Depends on the saw. I would not think that a 066 with a 100lbs of compression would be worth carrying around. Usually as the saw drops compression starting and idling become erratic and extra work. Compression testing gives a very limited amount of information and on this site is regarded with way way way more respect than it deserves. Just like the tach..
On most modern brands there is no need to tear down a saw to check rings, just pull the muffler and poke the rings.
No movement=stuck rings, tear it down and fix problems. Stuck rings are a symptom.
Very little push in= good
Very little side to side=good
Lots of movement everywhere=tear it down.