I'm at 100% for DL this year and around 98% for NW. Only EUAs I've missed this year have been two legs on NW on a Thursday evening (lots of consultant types returning home) when traveling on a bottom K fare for a personal trip. Most of my flights are for work on refundable (M or higher) fares. I think even Plats on NW have not had 100% sucess with EUA, especially on low fare buckets.