Thanks for the replies everyone. I'm still not convinced this is the best tank, in the sense of being a tank, rather than being a support class. I also think it is the most advanced job to use well. Since a lot of it's mitigation requires a lot of thought and knowledge of fights and reacting fast to whoever is going to take damage. It's decisions to heal too. Ultimately not the tanking class for me. I prefer self mitigation above all else. I love the GNB even if a bit squishy, but it has good self mitigation cds and streamlined group support that is easy to use, so you can just focus on tanking.

All the same, thank you for everyones feedback. It's a nice community here.