FTB,
I do not know the conditions where you work, ie taxes, pay, scheduling. Having said that, while it is true, that the pay at the majors is very, very good, it is purely seniority based and some of the arguments put forth here are valid. Also considering the "upheaval" currently going on in the US, more specifically UA still pursuing USAirways and Americans recent purchase of TWA. Who knows what will transpire with regards to seniority as well as furloughs, considering that the economy appears to be "slowing", as it was so gently put.
If you desire to return to the US for pressing personal reasons, I would certainly consider it, but the grass is not much greener here.
It is a hard choice and only one you can make. Best of luck.
D8