If only I could find x-ray specs in that dungeon.. i'm not really sure myself though. I suppose though, if you're going to beat either, it'd make sense to beat wilds as it has a reward that could be better than PoNR's, if it's known.
I finished the Path of No Return earlier today using Meloetta and the only thing of note at the end was a Mobile Scarf.
Seems like it just picks one or two of the "ultimate" hold items as the end reward there (Though the Kecleon shops on the last 10 floors sell them for an outrageous price and they can appear rarely on seemingly any floor, as well).
The Ultimate Wilds at least gives you some sort of proof that you finished it in the form of the Courage Crown. I'm currently trying to complete it with Virizion, and the selection of Pokemon there is making it feel considerably more difficult, and there seems to be less useful items around, too. The Pokemon also have team skills from the very start, whereas they only start showing up after floor 20 or so in the path.
Well, after having died a miserable death in 50s of the Ultimate Wilds, I can safely say that the enemy Pokemon in the place are WAY stronger then the ones in the Path of No Return.
I could actually take hits from the ones in the path, but I get two hit KO'd by the Pokemon in this place, which is rather problematic considering how much luck is involved in even hitting them due to their team skills... More jarringly, they actually have defenses that are high enough to survive getting hit by Virizion's Double Kick when everything else up to the point I died at was getting taken out by it in one use.
Apparently, they just decided to make floor 50 to 60 an absolute pain, as things eased up quite a bit once I got past that point, due to there no longer being any overpowered enemy Serperior, Samurott, and Emboar to deal with.
The Emboar, in particular, were nearly OHKOing me with Arm Hammer when I was level 18 as Keldeo, which is 70+ damage per hit.
I stopped at floor 66 for the time being, and feel relatively confident I can make it through, as I lucked out and found a pair of X-ray Specs on an early floor like I did with my successful Path of No Return run.
If there's one thing I can say for certain, it's that using a Pokemon with a ranged attack is practically a requirement if you plan on getting far, as the Intimidation, Tough, and Last Minute team skills combined together make it extremely difficult to reliably take down enemy Pokemon in close quarters without taking damage.