I can't remember if the Nitrix is a cast riser or machined aluminum. I think I remember hearing it was a Powermax with roller guards. If that is the case I would definitely pass.
Nitrux is an underrated bow. It uses the same riser as the powermax but that’s it. Has different limbs, limb pockets, cams, and has a roller guard. It’s a smooth shooting bow and tunes better than the powermax. Also has a bit better performance as well. I’ve set up several and they’ve all tuned up super easy.
The only person I've seen with one had it in the shop because his sight was wobbly. Had the sight bolts running through the quiver mounts and into the bow and they locked up. Made me double take and I noticed it was a new nitrux lol
I picked up a Nitrux the week it was released. Originally went into the shop to drop $$$ on an RX-1 and the owner said to hold off and check this bow that was just released out and to just draw it back before settling on an RX-1. Fell in love with it the moment I drew it back. So smooth and plus it was literally half the price fully equipped (rest, quiver, sight) of an RX-1 at the time. I have nothing but good things to say about it and feel it's an extremely underrated bow. Honestly can say I don't think I'll ever in the next 5-ish years need to even think about buying a new bow.
I bought my first Bow in 2015 and the nitrum aluminum bow shot better than the carbon spider but I went with carbon because...well carbon. I bought a new bow in 2017 and went to the shop with every intention of picking up a defiant carbon 34. I shot the aluminum bow from that year and it shot better for me again. After a few more arrows, and I did the right thing and bought the aluminum bow. It is a touch heavier and when it is really colder I can feel it through the front strap. Apart from that, it shoots like hell and is still capable of better accuracy than I can deliver ( I am reminded of this every time I go to the shop and the bow tech shoots tighter groups with it than me.).
There are far more knowledgeable people on this site than me on this and many other topics, but I would say shoot them booth, side by side if possible, a go with the one you shoot best.