For me it is a massive 6. The lich system rushed and recycled from the kingpin system what they teased us in an older devstream. The meele changes mostly nice but still there are some weapons which slowed down for no reason and have very bad attack animations. Another stuffs are mostly okay, honesty I cannot really say about much on the empyrean because I did not tested yet.
The new frames are okay, I mained the Gauss but my Volt remains the number one and Nidus the number two then Gauss. The warframe tweaks and reworks are fairly okay but none of it that great. The bugs and game breaks are happens with major changes so that is not surprised me at all. I think this year is a mediocre year for warframe, but I like the gas city rework but still on Earth the tileset is laggy a bit. At least they done some work on the game and hopefully in the next year they will work on the mods, reworking companions (AI-stats-usefulness) and finishing the meele rework and hopefully they will rid all the slow down animations.
The major content still there the New War and the Planes of Duviri.