The new nzap is very flexible and quite powerful, probably one of the best Sheldon's Picks weapons IMO.
The most important strength of the 83 is that it allows for the "tentatek role" of a team to use a Kraken, which allows for more flexibility in team comps and also allows for some weapons without Kraken or Bubbler to shine that would have otherwise put pressure on their teammates to make up for the lack of invincibility.
Generally, the 83 is best played by patiently and persistently painting and marking enemies, and stalking until it can act explosively and make plays with its CQC mobility and access to Krakens. The key is to know when to switch between painting and marking enemies, to assassinating or slaying. It's similar to tentatek in that regard, although its kit changes how it goes about map presence and playmaking.
In order to use the 83, you're going to have to get comfortable with the 4-shot kill. Contrary to popular opinion, I do not think that the nzap itself is bad in combat ─ it has not had a good slaying kit in the past but now it does. Once your aim is disciplined enough, the kill time is only 3 frames slower than tentatek, basically negligible. It allows you to be a tentatek with Kraken, and once you're at that level, you're going to be a terror.
You also need to understand how to use point sensors as a pressure tool, as both part of your explicit offense and a way to continue pressuring enemies when you need to stay back ─ marked enemies are going to take less risks than normal and allow you and your team opportunities to advance.
There are a lot of ways to build the 83, but I'll mention two example loadouts to think about:
Counter-Tank: It only takes 1 main and 1 sub of damage to be immune to defense up outside of fall-off damage. This is a big deal when approaching the whole "guess how much damage and defense are needed" game that tentateks and 52's play. The 83 can just win that game by running up to 1m1s damage, stacking a desired amount of defense, and filling in the rest with run speed. This allows the 83 to chew through all defense while simultaneously giving other weapons problems with its own defense. Low amounts of run speed can still be good on these builds because the nzap itself more or less gets one non-scaling main of run speed for free to begin with, resulting in an even more difficult-to-kill target. Alternatively, 1m1s damage can be added to pretty much any build to guarantee that the 83 is immune to defense up.
Example build: 1m1s damage, 1m6s defense, 1m2s run speed
Sanic Meter-Build: Comeback is great for the 83. Since it gives special charge and run speed, it allows the 83 to gain insane meter while returning to the map. Run speed means that more droplets land by themselves and paint maximum ground, and special charge means that all of that paint yields more meter. When combined with even more run speed and special charge, its allows the 83 to ferociously build and hold onto many Krakens per match. A bit of swim speed or damage can be used to top off the 83's combat effectiveness. Alternatively, Comeback can be added to many other builds to serve as a very effective means of getting meter back after death.
Example build: comeback, 1m3s run speed, 1m3s special charge, 3s swim speed
Hopefully that gets some ideas flowing. The 83 is quite flexible and can often be built to satisfy many needs on a team, so don't stop thinking about abilities I haven't listed here. Have fun!