Anyone have experience with this? I like the idea of keeping more heat in the combustion chamber. Just wondering what the longevity is of the ceramic? Will it burn off over time? Is it worth the added cost or not?

I do not know about longevity. Less heat transfer can help power... and also increase detonation. Lower CR may be required with the coating.

Don't waste your money.i tried it.Burned off after 25 passes.

Had my hemi pistons coated when they were made at Diamond back in 2006. Was done to help w/ detonation since this was a pump gas specific build. A lot of it has worn off over the years...can't say if it helped or not.

I have a lot of experience with coatings.If done right, and the correct type of coating it should last a long time.An old stroker VW engine i have has 75k miles on it with coated crowns and skirts,the coating is fine not lifting even on the one that had a little "issue" with a valve.Where the piston was impacted by the valve a little bit of coating is gone but you can't pick at it and get it to flake off.
If going the whole hog with coating this is how i would do it.
Ceramic coating,top of piston
Front of intake valve
Combustion chamber
Exhaust port
All of exhaust valve to where it sits against the guide
Piston skirt coating,
Piston skirt,
Underside of piston
Valve stems where it rides in the guide.
But all that being said if you keep heat in the chamber etc, you will have to reset your clearances cause the piston wont expand like before. Theres two places in the U. S where i'd spend my money on coatings are Polydyn in Houston. And Calico in North Carolina.Hope this helps.

Depending on what coating you use and what company, ive had the same pistons in my street beater that sees little actual miles but the coating has lasted over ten years now and I spray it hard from time to time.

I used calico and before that, long ago the only company that did it was the same company nasa used. Now its $300 or so, in the 80-s it was nearly 3k.