EPDs are very good at pointing direction. Human nature being what it is, bigger is always better...unless it's birth weight, then we are talking the quintessential pipe dream...curve bender!
EPD accuracy simply means that the data field is large enough that the measured EPD isn't likely to change...very little to do with actual reality.
All genetic response goes through environment. If an animal is not used in the same environment it was developed, the EPDs and actual data are of little, if any, value. Pork and poultry(and dairy to a large extent) are developed in controlled environments...apples and oranges in comparison to the beef industry(cow/calf).
My ignorance is a blessing!