Performance differences between new G6 cameras?

I'm looking to replace a Dahua/EmpireTech IPC-T54IR-ZE-S3 camera with an Ubiquiti camera, probably one of the new G6 cameras. The EmpireTech has 1/1.8" CMOS 4MP 2.7mm–12mm Vari-focal. The image quality and low light capability on the Dahua is great, but I just need to audio/event features from a proper Ubiquity camera. Looks like the G6 cameras have the same size sensor, albeit 8k vs 4k. I can't see stats on aperture size on the Unifi cameras - I imagine low light performance might be a bit worse on the Ubiquity cameras, but think I'm willing to accept that.

Seems my main choice is between the G6 Instant vs G6 Bullet. Tech specs seem similar. Additional IR illumination of the Bullet is not an attraction and most other specs seem identical. Prefer form factor of Instant, but given I've got ethernet wired, the Bullet is more attractive. Would prefer not to congest my wifi.

Wondering:

1. Is there anything I'm missing in terms of performance (minus IR reach) between the G6 instant/bullet? Camera will be used indoors, so IP rating/tamper resistance also not relevant.

2. I would like consistent FPS if possible. I'm wondering if wifi on G6 might lead to greater FPS drops?

Thanks!