Been playing the shit out of this lately and compiled some thoughts on the game.
Weapons
Recoil feels weird across the board. Shooting on automatic IRL is more controllable because you can pull the gun closer to your torso and direct the recoil into your center mass, where that energy has more room to dissipate. I don't know if attachments do anything quite yet, if not that's no big deal, but for the most part the assault rifles should have similar recoil "kick" and a near similar pattern. The M4A1 in game and the SR-16 have similar barrel lengths and the same direct impingement gas system and fire identical ammunition. They should have near identical recoil before attachments are taken into account. The 416 ought be extremely similar as well. The SBR-300, in 300 Blackout, should be a little bit more recoil shot per shot, but not incredibly much because 300 black was designed to not kick that much harder than 5.56. The SA-58 obviously ought to kick like a mule, being a short barreled FN FAL and holy goddamn shit does 7.62 kick out of a short barrel. Additionally, most of the assault rifles support 3 round burst fire modes and I believe the H&K offers a trigger group for the 416 that is semi/burst/full for police/military purchase.
There's a lot of people in the official discord doing the "I played SWAT 4 and know an M4A1 will have recoil that can't be controlled on full auto" routine, and 5.56 isn't really that uncontrollable in my experience. The guy that showed me to shoot, when I asked him about the recoil, showed the light recoil of the M4A1 by magdumping from his crotch. Unless you are a stick armed weakling, or perhaps that one guy from Polygon, you can control a 5.56 on auto.
Submachine guns would benefit from having burst fire modes to capitalize on their low recoil impulse and I believe H&K and SIG offer S/B/A trigger groups for LE/military purchasers. Otherwise the SMGs feel pretty nice. Maybe ammo options for FMJ or JHP ammo to better deal with situations at hand. The car dealership level has dudes in soft body armor that just ignore SMG rounds, so being able to use JHPs to defeat them would be nice.
Shotguns need differentiation. There's no reason to take the 870 over the M4 because they have identical capacities, identical attachments, and the same ammo but one can be fired on semi. Why take the pump? Ammo options like slugs or low power for suppressed use would be my suggestion to give the 870 a reason to live. Attachment options need to be a thing for shotguns. Right now the only options that matter are either a spread choke that, counterintuitively, increases pellet spread and a muzzle brake that reduces recoil. A real choke that tightens spread, big suppressor cans, etc feel needed to give shotguns a reason to exist. Their big saving grace is that the health system is very similar to CoDs in that repeated hits anywhere on the body can kill things, even if the hits are non fatal. This means shotguns are ridiculously lethal to everything because catching even half the pellets on target will drop most anything.
Armor
Body armor needs looking at. The armor we wear is of the correct thickness to be either Level 3+ or 4 plates on front and back. As is, suspects with 9mm pistols can double tap our armor and finish us off in under a second, despite this armor being rated to resist current generation M855A1 rounds. Even armor pauldrons, once exclusively soft armor, are increasingly being fitted with ceramic or steel inserts. Either body armor needs to behave authentically, in that it no sells things it's rated to resist, or we need to be given Level 3A soft armor instead like a beat or school cop. A Makarov cannot, repeat cannot, breach the body armor we wear, or the 3A ballistic Ops Core helmets we wear. This kind of armor is why stuff like M995 AP rounds exist. As is, the overwhelming majority of the criminals in game use 9mms. A small handful use P90s and MP5s. A couple I've seen use assault rifles and a precious few have RPDs (!) in bigger maps. It feels a bit weird to see a suspect with a Makarov or a Tec-9 or something to that effect kill someone wearing body armor designed to resist green tip ammo. The P90s and ARs and RPDs are all nicely dangerous, but it sort of deflates the tension when a nignog with a Tec-9 is equally as dangerous to my body armor as a skinhead with an RPD. It's consistently inconsistent and it deflates a lot of the tension of the game. Dudes with handguns are a SWAT team's breakfast, for lack of a better term, and carelessness should be the big killer dealing with dudes using 9mm.
AI
This is the thorny one. The AI varies wildly between drunken comedy buddy cop movie and T-800, sometimes in the same AI. There needs to be a larger gradient between detection and reaction and the AI's knowledge of player position needs to be nerfed a bit. If they detect you, even if you're completely unmoving through a wall, they can reliably wallbang you with clean headshots and they'll follow your movement through solid objects. Either the AI detects where we are based on what we see (if we see a specific part of a wall, the AI extrapolates where we are based on that) or it's being fed information from the game engine once they change state from passive to combat. This makes them inconsistent even among their "factions" and it makes them extremely lethal once they detect the player. It also makes it frustrating as a player to get absolutely demolished by an AI in a split second when they wallbang the entire team with headshots even with no feasible way of knowing where we are. There's also an interesting habit I've noticed in the AI where they will flee from direct confrontation to run a loop around the map and flank you. With no way for the player to run, this is something of an issue. There's also animation issues with the AI, where they'll just stop all animations but still move and shoot. I had one literally rotate like a pillar with gun clutched to his chest and double tap me with a shotgun without actually moving. I'm not sure if the animations are a latency issue, but I have seen them do this as client and as host so I don't think it's networking related.
Maps
Some of the maps feel too large for a 4 man team to feasibly be expected to be responsible for securing. Hotel feels like one of those maps where there would feasibly be more than one SWAT team on scene at a time to cover that much space. AI spawns and placements feel like they could be diversified a bit or you have this situation where you can go into a map and be like "oh the AI spawns here and they patrol there" etc. If this game is meant to be infinitely replayable then these need to be diversified. I'd probably also adjust some of the lighting. Most of the maps don't feel like they need NVs and the one or two that does still isn't that dark. Taking some inspiration from The Forest where night is not just dark, but actually black would work nicely. This could also pair with something like an IR flashlight instead of an IR laser. Most of the maps would benefit a bit from better lighting. RoN does the invisible light thing a lot of other games do, so some places are lit oddly. It makes some maps, like the Farm, feel really inconsistent. But the placement of invisible lighting is also really well done in some maps and adds to the atmosphere.