I did the Beta. My PlanetSide outfit played release for a while. They've all returned to PlanetSide. It pales in comparison to PlanetSide in scope and strategy required.
It is a solid game though. However, pretty much like AO, the larger Agencies dominate the game.
Some notes (can be good or bad, depending on your perspective):
1. It is really only a 10v10, squad vs. squad fight. They claim MMOFPS, but they are not an MMOFPS. Some talk of them going to larger fights.
2. No vehicles. No plans that I've seen.
3. Must pay for AvA access.
Global Agenda was a letdown for me. Though, I'm used to PlanetSide style fights. Massive fronts where fights are up to 133 vs 133 vs 133, with the full battery of vehicles (air and ground).
However, I have been monitoring Earthrise (
http://www.play-earthrise.com/). Sandbox shooter. Has Tabula Rasa-like game mechanics. We'll see. I'm not putting a lot of hope into it.