LGA has an updated security checkpoint at Finger B which is where Airtran operates. There are no traditional carriers operating out of B to my recollection, so there is no "elite" line needed per se. My recent experience with Airtran (first and only) was fine on the ground, but was lacking in the air. Even with lowered expectations, they managed to underperform (product only). Operationally however, they were fine.

The more I think about it, the more I think this is the model US aspires to...but without the low fares....