My first impression is ok. This new stuff is great for players who dont run dungeons anymore because their bag is filled with 1000+ 6-star artifacts, all rolled up too.
For early to mid game players, this dungeon should be avoided. Your time and energy spent there woould be best direccted to actually farm gear. God knows we need a lot of them to gear dozens and dozens of characters properly.
As for the ascencion mechanics, unless you're looking to make the world's strongest (insert champion name here), you'll probably want to skip ascending weapons/helmets/shields. Guaranteed flat stats on those wont give you a whole lot.
For the bottom pieces, my initial take would be that the absolute best pieces to upgrade will be your crit damage gloves. Crit rate gloves a close 2nd. These 2 stats are harder to obtain, compared to speed, res, accuracy, or % stats. Imagine getting a mythic 6-star crit damage glove with quad roll of crit rate and a bonus crit rate roll on top! HUGE! Ya i'm dreaming here LOL, but... it WILL be 'possible"