I have to admit that looking back Duviri is probably my favorite update to Warframe in terms of content and gameplay.
The circuit is a fun addition that is both difficult at times but also scales exponentially into the power fantasy territory without ruining the overall balance since it's just borrowed/temporary power. Searching for fragments is fun, the objectives go through pretty fast (especially now that defense is changed) and maps are easy to navigate and fun to fight in.
The open world Duviri is also a joy to explore and do missions in to the point that I am disappointed when we get the undercroft stage. The area is beautiful, I even somewhat enjoy the drifter combat despite it being atrocious. Still better than regular warframe melee I guess :P
The wyrm fight has got to be one of the best boss fights they've made, especially in steel path. I only wish I didn't have to do them so many times repeatedly for those damn pathos clamps.
With the addition of kullervo and new arcanes they also addressed the initial issue of duviri just not having enough proper rewards in it, and hopefully they keep adding to it even more. I haven't had the chance to test the incarnon adapters yet so dunno how that holds up but it also seems like something that can be easily expanded in the future.
TL;DR Duviri is a pretty good and fun update all things considered. I'm enjoying it more than the previous open worlds for sure, I just hope it gets some QoL updates and new rewards so we have a reason to go back to it often.
I found it fun for a while but the amount of grind and repetition got on my nerves. Duviri does look very good and actually exploring it was quite fun as well. I did grind it pretty hard and got everything i wanted out of it apart from incarnon adapters. So basically i enjoyed it until i got the stuff i wanted outside of the steel path at which point it turned into a complete chore.
I really hate the random gear myself. While its usually fine for normal mode, all the worthwhile stuff is locked behind the steel path circuit. Being stuck with random gear in that is terrible enough, but the entire game mode is also dull as all hell. Can't even trade for the adapters as they are untradable for some reason. So this new direction with weekly crap at steel path levels is what finally made me drop the entire game. At least for the time being.
I've logged on a few times but i look around and all there is to do where i actually go towards something i want is either nightwave, archon hunts, khal (worst gamemode in the game) or steel path circuit. The only one i would consider fun is the nightwave stuff since there i can play the way i want.