The change machine where I work exchanges these coins for paper bills. Automated checkout machines are unfazed by these, but human clerks are somewhat confused.
About six years ago when the Sacajawea coin came out, my son was home on leave and we took a drive in the Virginia hills. I had a few of the coins in my pocket when we went into a tourist trap story in Sperryville, VA. I bought some peanuts and dropped three of the coins on the counter. The really old gentleman behind the counter, in a heartbeat, picked one of them up and in a voice I still have ringing in my ear he said, "What the hell?" I thought he was going to bite it to see if it was gold.