I recently made the jump from overall length to comparator length.
I use the hornady doodad on the calipers to measure the shoulder to verify that my sizer is set right. Then I use a wilson case gauge on all the cases before they go in the box to make sure they are all in spec and without bulges that would make them chamber poorly.
The wilson case gauge is pretty much indestructable, but you need to clean it with a chamber brush from time to time. The Hornady comparator would be a lot cooler if it wasn't made out of soft aluminum, but it's durable enough for a precision measuring instrument.
I had the bullet comparator insert for a while, but only started using it recently when I got the hornady bullet seating set up to actually measure how far away the lands are.
It's really not that much harder to use than plain calipers. I was just being lazy before.
If you want something durable, you can use this:
It's the same concept but it doesn't stay attached to the calipers like the hornady one does. I like the hornady system better.