would i be better off getting fx35 or fx45?
i have owned and worked on plenty of vq30de and vq35de's so i know a lot about them. but what about the 4.5L(vk45de) and 5.6L (vk56de)?? are they as good as the vq's (jd power awards every year)? i have had several maximas and have a qx4 now. it is not big enough.
fx35 and fx45 dont have much back seat room either.
qx56 has a lot of back seat room

Yes, you would be better off with an FX.

I do know that the 04 Armada and QX56 have grossly undersized brakes that were a source of very, very poor reliability ratings for those cars in their first year. Statistically, one of the least reliable vehicles ever made.

I would pass.