Oz,
it all comes down to how badly you want a change. If staying with QF means you become depressive, divorced,and desperate for something different then EK will be fine for some time. How long all depends on your abillity to adapt to how things are done here. As stated above, lots of people have complaints about EK, myself included, but you will get the same from any pilot group. QF as well. I came here from OZ under simmilar circumstances and have no regrets at all. However I have been here for too long now and am in need of a change. Finding something that competes with EK and takes DECs is a problem. You will have to face the same problem if you come here, the gulf is not a long term career option for westeners.
There are no guarantees in this job, but with the number of planes on order at EK and what will be ordered shortly you should get an upgrade in about 3-5 years and fly to a lot of very interesting/demanding destinations. You will enjoy life here but as with anything eventually you will tire of it and get p_ssed off with your lot in life again. Then you can move on and explore another part of the world...