Used my EasyPass-RTP for the first time this month. When OK, except the "helper" at the gates saw my US passport and insisted I was in the wrong place. I kept trying to tell him I had registered and he kept insisting I had to go over to the other line. I still had my enrollment form and showed it to him and he finally let me use the gates. I probably didn't save any time -- but hopefully I will in the future.
I do have a question though -- for the exit check can I also use the EU gates? They do have automatic gates for US (and other countries) but sometimes the line backs up and you have to wait until enough clears so that you can reach them. In my case, it was a large group of young people -- under 18 -- so they couldn't use the automatic gates and the line backed up quite far. I was eying the empty EU gates but wasn't sure if EasyPass-RTP lets you use them.