I'm surprised this hasn't been addressed yet in LCG.
There are some pretty cool dragon synergy cards and the dragon reprints are fairly cheap - but only two of them are really playable and Rhaegal is more of a Valar shield than anything else. So the dragon stuff isn't shining as brightly as it might.
Plus - the "adult" dragons are un-Nedly as hell and always have been.
Dunno which Hatchlings I want the most. Its close between the 5K ambush ones and the Crown of Suns era attachment ones. Either set would be handy and appreciated (not that I am playing a lot of Targ or anything).