My experience this week AUS-LAX nonstop and return, was A28 and A39 using EBCI. Tickets were purchased about 5 days in advance. Going I was able to get the seat with all the legroom, and returning, a near COS took the window so the middle stayed empty and might have been the only empty middle on the flight. I did use my trick of opening up the wsj paper in a big way to help mask the seat being available.
So EBCI works for me and I consider it a good value. In contrast, Mrs. K and I had to purchase last minute tckts on AA 1/2 of which was on AA regional. Couldn't get seats in advance due to the fare we purchased - only at the gate. We also had the privilege of paying to check bags.