Might be a bit on the nose heavy side, given the fact that the plane is for up to .82 4 stroke (which is the Saito .82 which has the footprint of the Saito .72 and is only a tiny bit heavier). This is a profile plane which is quite light, so the additional weight of a .90 4 stroke may be a bit counter productive for 3D learning. You'll have to add weight in the back, as for 3D flying you want the CG to be a bit more back (not too much, of course), so I'd recommend a .70 size OS Surpass.

I ordered that same plane and I'm planning on putting a Saito .72 (which I already have) in it, but maybe I'll even put a 2 stroke OS in it (for weight reasons). Not sure about that yet.