Railjack is pretty mixed for me.
I liked the Grineer missions where your squad could complete different objectives in parallel/spit the squad up to perform different tasks, and the missions also felt somewhat unique compared to the base game. Corpus missions on the other hand just feels like playing a mission to play some other game mode already available on the base star chart.
I don’t like the current energy system for ship abilities, it feels like it was balanced poorly because it’s dependant on which warframe you chose, and feels like certain warframes were nerfed before the system was even implemented. Energy costs scale poorly with Hildryn, she was nerfed before the update dropped because people wanted to make use of Shield regen for casting abilities. If I remember correctly, this was also part of the reason Dispensary’s duration was nerfed as a Helminth ability when the helminth system was added.
Current combat in space is an improvement over what we had in early versions of railjack; if the host had bad weapons for their railjack you had to put up with it because enemies heavily resisted archgun damage. The Amesha was and probably still is the only usable archwing for these missions. Gunnery 10 still feels like it’s a nerf, I just prefer the feeling of having control over what I’m shooting at and not that it’s automated for me, the extra overheat on top of that doesn’t help either though. Other people might appreciate the lock-on, but it probably belongs under an accessibility setting rather than the last unlock for an intrinsic.
Not sure if void fissures ever changed, before if you were moving too fast through the level, you would just hit multiple void fissures and die. I think they might have just been spawning them directly on the player as the tiles loaded.
Overall, I think most of the game mode needs a rework and other game modes to differentiate it from the base game.
Styanax was pretty fun to play, I had it modded to be a shield tank before his Final Stand augment was added, so he had pretty good survivability. His 1 without his augment feels terrible to use though because it requires you to hit a target to group enemies and if that enemy has Overguard it won’t group any of the other enemies around even if they aren’t protected by Overguard. It doesn’t help that Overguard is getting put on everything in recent updates, his augment does let you hit the ground instead but that feels more like a band-aid instead of just letting it group enemies that aren’t CC immune.
He had pretty good energy management with rally point and tharros strike helped with removing armor from tankier enemies before killing them to replenish your shields. I don’t think Final Stand was useful on its own, but it is a very good ability if you’re using its augment.