Hi Ryan,
I fished out of trees and fishes with ocean blue in April last year. They run a pretty good operation and you get the 5 star treatment from the moment you step off the plane. If you're looking to target GTs while over there, then this trip isn't for you. I went on a trip that was advertised as a GT and dogtooth fishing adventure, but in reality all you do is jig for doggies for most of the time. Don't get me wrong I love jigging for doggies ect., and they fight like no other fish, But they are very misleading with their advertising of their charters. We spent maybe 4 hours in total casting for GTs over the 5 days with the remaining time was spent slowly trolling for yellowfin around the FADs. Even the guides and deckies admitted that they don't see many GTs, don't get me wrong they get a few, most of them by catch, but where you fish with them is not well known for catching GTs.
If you're looking for a place to catch plenty of GTs and somewhere nice to take the family, I don't reckon you can go past Cairns or Port Douglas in Far North Queensland . You'll catch plenty of GTs upto 20kgs while fishing out at the GBR. It's lot harder to catch the larger models of 30kg and above, but you'll have plenty of fun in the smaller models.
I hope that helps.
Cheers, Matt