I am considering buying an Aimpoint Comp ML3. I've not held the exact model but I understand it has a new rubber jacket or coating on it that was not previously on Aimpoints.

Are there any issues with mounting it?
Has the tube size been reduced to make up for the exterior coating so it will still fit rings precisely?
Is the mounting stable considering the ring is clamping on rubber?
Cosmetically is there any damage or just plain funk with the ring smushing into the rubber?

Lastly, is the Comp ML3 worth a damn?

Thanks for the help.

Actually the rubber is designed to mount over the rings.  I know the A.R.M.S. mount for the ML2 works on the ML3 so I believe the tube diameter is the same.

Thans for the info. I've had a number of responses that clarified that point. Makes sense.

I have a Comp M3 and the rubber shield slips on AFTER the unit is mounted.  Without the shield, the M3 looks just like the M2.  

I don't use the rubber shield on my unit because it's too "baggy" ; it's made to fit scope mounts that have the bolt flanges at the top or the sides, so if your bolt flanges are on the sides, then there's an empty rubber pocket on the top, or vice versa.