Your dragon will do very well, but if you are prepared to put some time and effort into it, you can do quite a bit better I think. I'm with whoever it was that posted about the demon temple on Fire Island. That is my favourite place to farm them.
I take my hiryu, lead off all the other spawn that is in the way, then precast invis, run up, cast invis, lore it, and if I don't like it, I lead it to the front of the temple and kill it. It takes a bit of vetting (well actually a ton of vetting...), but I can kill them fairly quickly, and then I get the pleasure of looting them because I lead them off a bit. I always farm them on the Felucca side, so that is 60 barbed hides each, and 14 scales, which is a nice bonus.
It took me two weeks of pretty steady farming (several hours a day) to find one that really made me happy, but to be honest, that was a lot faster than I expected find a good one. I've been surprised by how many truly exceptional dragons I have seen, so it can be done, and it can be done without spending the two years it took me to find an amazing cu sidhe, or rune beetle.
I'd have to say that it is easier to find an exceptional greater dragon than it is to find either of those, which really strikes me as odd, given the stat ranges on them, yet more proof that stats are generated in odd ways on mobs. It is almost as if if they have one or two stats that are exceptional, they'll have a much better chance of having other stats that are exceptional as well.
However, that could just be the rng, because we all know that the rng tends to function in streaks.