I've been to both several times.
Both are great, and both can get very crowded. B'more has 3 courses, ETAR has 8. If you can, do all your shooting on the first day or very early or late in the following days. You will test your patience if you hit a course at mid-day on Saturday.
B'more has a few dozen vendors, ETAR has 150.
B'more has the best pit beef sandwiches in the world, ETAR has food (it will keep you alive).
B'more has nice grass field for camping, ETAR has mud.
B'more gets a good exibition archer for entertainment, ETAR gets the same plus various well known speakers and informative demonstrations.
Hard to pick my favorite. I like them both.