Do it. They made a strategic error in not doing it to begin with and when you don't change, you don't last. They should:|
1. Hold a major dealer forum on the issue (read they're doing it) and let them voice pros and cons in an orderly fashion (yeah, right)
2. Make the switch to 1/2 grades
3. Offer break-even or loss-leading promotion to re-slab into 1/2 point grades
AND HERE'S THE BIGGEE:
Re-do the holders at the same time using a break down of grading on the back and improve upon all aspects of the holder, including inner sleeve (ala BVG) and neutral but classy labels (silver for all grades except gold for 9 and 10).
PSA does this and they're going to lose money for 1/2 year. However, if they do it right; they become the giant on top of the hill.
As for their customer service, they better correct that as well.
Enjoy Your Collection & SKOL VIKINGS!