Actually I went from nirvana to r8 on my archer and plan on doing that for my wizzie. Why? Because ultimately you WILL want r8. Especially if you plan on being a competitive pvp'er. And in my eyes, I saw dragon gear as an expense that isn't truly worth it if you're only gonna replace most if not all of the pieces, and unless you have alts that you plan on getting to 150, that 500-ish EC you pay for a full set of dragon gear is just gonna go to waste (sure you can sell it, but...). So I just cut out the middle man so to speak.
I got lucky quickly on my archer's gear (I went a low-maintenance build on him so I wasn't worried about getting -int on every piece that can get it), but my wizzie? Not so much--but I'm one of the crazy ones who started reforging a couple of levels early so when I can use it, it's actually usable.
In YOUR case, because you are converting from PRIMAL (are you sure it's Primal and not Demonic? Because there is no comparison) to endgame gear and just cutting out nirvana gear altogether, I'd go Dragon first.
