I was looking at the gear section, and I noticed that Sensors are now bought at a system ratting, including sensor arrays, which seems to have been explicitly designed to solve the issues with upgrading drone & vehicle sensor ratings in 4th edition. Drones have an array at the listed rating. In theory, you can buy a better array, but to a max rating set by the size of drone. Alternatively, you could buy arrays with non-standard sensor load outs, if that's your thing.
The fun part is that it appears that you can also put a sensor or sensory array into almost anything with capacity. The "Sensor Housing" table on page 446 has some interesting implications, including cyberlimbs.
It looks like you can install a single sensor system or sensory array into my cyberlimb using limb capacity. The max rating of the system is fairly low for "headware," (systems installed in a cyber-skull I guess?) although better for "cyberlimbs." It appears to be an interesting option for anyone that wanted to put a MAD Scanner in their arm, or stick a camera in their hand for looking around corners, etc. You'll note that there are already a lot of implant sensor systems in the augmentation section, but those systems tend to allow higher ratings and can be implanted into a body instead of a cyberlimb, although many have a capacity ratings as well. In a few cases the systems probably work a bit different. An ultrasound scanner or camera installed in a cyberlimb isn't the same thing as the implanted Ultrasound headware or cybereyes, as it doesn't integrate into your you personal perceptions so much as provide a data feed.
A potentially confusing point is that if you choose a camera or microphone as a sensor function, it's rating becomes capacity for vision and audio enhancements. Yup, capacity in capacity confusion is still around.
Oddly enough, although helmets have capacity 6, they are expressly for vision enhancements, trode nets, etc.... and helmets aren't listed on the sensor housing table. It doesn't look like you can install special sensor systems into the helmet. If you want a non-audio/visual sensor on your helm, you'll apparently need to stick it in an RFID tag and attach it to the helmet?
There is also an interesting implication to the max rating table: Handheld scanners (like what a security guard might wave over you when you enter a building) have a max rating of 3. A wall mounted sensor, like what you might need to walk past in security check point, caps out at ratting 4. A sensor array implanted in a cyber-arm has a max rating of 5, so it would seem that really secure check points will have augmented security guards giving you a pat down/scan. In order to get a better sensor ratting you either need a vehicle or a seriously dedicated security apparatus like you'd encounter at an airport.
A single sensor array takes up 6 capacity, but that means a rating 4 security scanning cyberlimb or security checkpoint wall mount sensor array could have a Cyberware scanner, MAD Scanner, Radio Signal/Bug Scanner, Olfactory Scanner (to look for toxic, poisonous, and explosive chemical traces), Geiger counter, a Camera with vision enhancements, a speaker with audio enhancements, and an Ultrasound sensor. $4000+audio/visual enhancement prices. I'd lean towards Thermographic, Visual Enhancement 3, Spatial Recognizer, Select Sound Filter 2. I think that's about $7,500 for a security check point with a lot of capabilities.
I'm not sure how the audio/visual enhancement availability rules work here. A Sensory array is availability 7, and can include a camera at availability 0, on which you can apply thermogrpahic vision (+6). So does that push the camera to 6 (0+6), or does it push the entire sensor array to 13 (7+6)?