I play Rebel, Republic, and Empire. Still have Resistance, but I don't really 'feel' the faction.
If it weren't for Republic, I wouldn't have anything that gets me excited to buy new things. This is the first year since I've been playing where I don't think I am going to spend up to my budget for X-wing (V-Wing and Actis will likely be left as gift options for December). And I'm pretty sure I only hit my budget last year because I picked up epic ships.
I'm not really bored with my options for casual, I just hop factions for a different feel. But I do get frustrated sometimes looking at the toys the factions I don't play get. RZ2 vs RZ1. Side slip. Networked calculations. Heroic. It would just feel nice to be included in some of the new toys. And to be excited to purchase things.
