I would like to know to hear some info about differences between CO2 and Excimers laser - not the technology itself, but i would like to focus on performance.

"In my carrier" i have used two CO2 lasers and i have problems with "stability" of engravings - or visibility after the hardcoating.
By stability of engravings i mean that 95% are ok and the rest are weaker at all or some of the parts of particular engraving are waker than rest.
The problem doesn't lie in strong minus lenses or strong plus lenses - it seems to me that instability occurs randomly.
I was told that solution of this problem could be in replacing of CO2 laser by excimer or to change the strip off process after hardcoat.

Does anybody have or had the same issues ? What has helped ?
Is there any method how to measure the stability of the laser ?
I know that by industrial lasers used for cutting are kind of absorbers being used, but there is also a bigger power.