We buy the EBCI. It automatically checks you in at the 36 hour mark so you get an earlier boarding position.
Wow..Im so anxious about this process...my little guys arent under 4, so Im afraid we will not end up together, I cant imagine not sitting with them..
Can you purchase the EBCI after you've already bought your tickets?
My family of 5 has flown southwest and have always managed to sit together. We do pay the extra for the early bird automatic check in, and it's worth it.