8/10 and seems to only get better with time... when Sony keeps to themselves, at least.
Sony fiasco aside, the game is phenomenal. Good control feel (M&K for me), game systems make sense and are well-balanced, a plethora of difficulties so you can play casual or intense, enemy diversity and aggression that is interesting and fun but challenging, a nonstop flow of updates and patches... it's just so much.
Strongest point: the live service. I've played a lot (maybe too much) Destiny 2, so I'm wary of live services at this point. Arrowhead is doing it right. The story is just enough to keep the player engaged with what's going on, IRL whoopsies are jokingly explained in the game lore updates, and what the player base accomplishes feels like it has actual consequences and carries the risk of failure. Absolute standing ovation to the live service team there.
Weakest point: FOR ME, the game falls apart with its matchmaking. When I'm playing with friends, the game is a hoot; we laugh, we panic, we laugh more, we slaughter aliens in droves, it's a great time. Solo, the game is very challenging and the feel shifts dramatically, but it's still good. If I'm trying to get into games with other people, it takes 5-10 tries to find someone who is not AFK, who is not going to immediately boot me because their friend wants to join, and whose connection doesn't fight mine and cause me to disconnect early on. Some of this will probably be solved over time as Arrowhead fine tunes servers and whittles out connection bugs, but spending 15 minutes just trying to get into a game... it's not fun. I'll go drop $250 on Tarkov if I want to do that /s
Gripes aside, the game is amazing and the devs are doing everything in their power to make it better every week. If you like alien shooters, grab some friends and give this a shot.

TL;DR: Lightfall is fun, but did not match many people's expectations. Bungie left important story threads dangling and continues to struggle with game balance and stability. But… that doesn't stop it from being *fun*.
If you're a veteran of the series, it's worth your time for the entertainment value. If you're new, test out the free New Light version first.

The Good:
-The Armor Mod system is highly approachable and intuitive.
-In-game Loadouts make changing between activities much easier; less need for DIM.
-Strand. High mobility, awesome visual and sound effects, and it's just fun being space Spiderman. There's even a repeatable gauntlet to prove your speed and efficacy with the subclass.
-New exotic mission. Pulls on some old story strings while delivering a moderately challenging mission and fun rewards.
-Neomuna. The new destination is gorgeous, with interesting lore and immersive patrols. Public events are challenging and, for now, worthwhile.

The Bad:
-The Armor Mod system feels neutered. We were building model airplanes and we're back to using Legos.
-Half a dozen different mods, exotic items, and other game elements have already been disabled in the first week of the DLC launch. This happens every launch but doesn't make it okay.
-Voice acting. Perhaps the most immersion-breaking moments were some of Osiris's voice lines. There are moments that the voice actor smashed, that his emotion comes through brilliantly. Then there was the "you're our only hope" line, that could've been delivered better by your average middle school theater rookie.
-Commendations. An interesting system that could certainly be encouraging and rewarding eventually, but not yet. And linking them to Guardian Rank progression was a predictably poor choice.

The Divisive:
-Nimbus, our main contact on Neptune. Their personality and dialogue seems to have one of two effects: 1) laughing out loud at their lighthearted, naïve humor; or 2) immersion-breaking dismissal of major emotional plot points.

The Confusing:
-Certain story elements including [that thing we're trying to protect] and [that other thing we're trying to protect] are clear as mud. The conversation with the two at the Tower post-campaign felt amnestic, like I had missed an important cutscene or previous dialogue. And while the full nature of the [thing on Neomuna] is never explained, the bigger failing is that it is never explained *why* we aren't told any details.

Summary:
Lightfall has been a whole lot of fun, but it has helped to have the right perspective. Thinking of this as the "Beyond Light" of Strand, this was a highly satisfactory campaign with plenty of exciting, entertaining moments and humor that landed well with me. The futuristic city atmosphere matched the mix of humor and horror of the story. It was a step forward in explaining the Light versus Darkness in the universe and our interactions with them. There were unexpected twists along the way.
But it was not the Witch Queen. Not only did it fail to answer many of the questions we had, it developed more confusion while dancing around the story answers we wanted. We have a new, unexpected power, but are no closer to ending the conflict that has now moved well past our doorstep.
Intentional mis-marketing? I don't think so. But poorly-set expectations for the penultimate DLC in a decade-long battle of epic proportions.