I have kept a couple. Just found 2 x 2005 S, but they don't really look that frosty, so I'll toss them back. I found a 1994 P which is prook like and in MS shape. That'll go back too. HOTN
Came across 2 full rolls of 70's and 80's proof halves at the bank last month. I bought a Dansco for halves with proofs that will be here on Wed.
So far I have only pulled a Maryland and a Bicentennial proof from circulation. Since I am a Washington junkie, I kept them.