I hate to make the first comment a grammar nitpick, but the title should be, "The Tenants receives the Manhattan Update." The Tenants is the proper title of a work, and should always be treated as singular (unless you construct the sentence something like: "Everyone's copies of The Tenants have received the Manhattan Update," though in that case, have received... is referring to copies, not to the title itself).

I also keep watching from the sidelines for now.

According to one developer called vritto it means many new bugs. :-)

Well sadly with this update and it being the biggest one it's going to be released with many bugs, which is good because then we have more eyes finding these bugs that in the end helps us fix them and this is also the prime time to tweak anything that needs to be tweaked with feedback on it.

Visit their Manhattan Update Steam page for a list of changes and additions.

I have picked up the game during the current sale and after playing for a few hours (and owning 4 properties) it seems that the game gets slower and more sluggish during all renovation actions and sometimes also when you scroll around the map.

Unfortunately there are also a lot of tries to 'phone home' built into the 'offline installer': the game tries to connect to the internet at startup (which my non-microsoft firewall prevents) and then (according to the player log) rather often tries to connect to
config.uca.cloud.unity3d.com
ancientforgestudio.com
perf-events.cloud.unity3d.com

And also in the player log: galaxy exceptions/error messages which should not happen at all if you install a 'clean' (i. e. galaxy-free) offline installer version of the game. One example:
[GOG Galaxy] Committing changes
(Filename: C:\buildslave\unity\build\Runtime/Export/Debug/Debug.bindings.h Line: 39)
...
[GOG Galaxy] Stat STAT_RENOVATION_JOBS value could not be updated for reason: Galaxy.Api.GalaxyInstance+UnauthorizedAccessError: SetStatInt: not signed in
at Galaxy.Api.IStats.SetStatInt (System.String name, System.Int32 value) [0x0001c] in <892c7be5422b43f9b8f250d633c44d71>:0
at Tenants.Platforms.GOG.GOGAchievementsProvider.StoreStats () [0x0002e] in <84c53b509b234cdda21c7c073107782a>:0
(Filename: C:\buildslave\unity\build\Runtime/Export/Debug/Debug.bindings.h Line: 39)

@gog.com & ancient forge studio: please provide future updates of the game with more privacy options for players (e. g. opt-out options which make it a PLAYER/CUSTOMER DECISION if data is sent out via the internet while playing) and remove all galaxy upload trials from the code of the offline installer files!

Apart from that I like the game and hope that it will get another update soon...

p.s.: it seems that on steam customers already able get version 9.0d of the game since yesterday while gog customers are still on 9.0b and - again - waiting longer for updates :-(...