Mark, it depends entirely on the area which you're fishing. If you're fishing in a really shallow nasty area, 25kg GTs will give you an absolute hammering even if you are fishing 100lb braid. At Shoalwater, all of us experienced being smashed by fish this size (and smaller) and we were fishing from 80lb to 130lb braid. Where you've got big currents, shallow water and nasty bommies, GTs are as tough as any fishing challenge.
If on the other hand you're fishing in completely open water, you could land a very big fish on 10kg line.
You're fishing PE4 and targeting GTs up to 25kgs. If there is any cover (reef, bommie, rocks etc) for the fish in the area you're fishing, I'd suggest you're actually heavily undergunned at the moment. With PE2, All I will say is good luck! I suppose you could do something I have always wanted to do but never done and that is free spool as soon as the fish is hooked and wait for it to swim into a clearer area before trying to fight it!
