Usually when compression goes, they get difficult to tune and don't hold an idle well.
As for feel, it varies. I have had motors that when cold, you could spin the flywheel with ease even with the plug in. It would run like crap for a few laps but once it warmed up it was a rocket. I also have a motor right now that has at least 4 gallons on it yet it is still so freaking tight that it locks up on the starter box, hot or cold. It's a major pain in the ass to get started but it goes like stink on the track.
Sean. Certified speed crazed mowron.
Team Shepherd USA