My first attempt at a 6s HD race quad, and I'm absolutely in love with it. Overall was a very easy build, but I have a few critical notes for anyone who wants to build this quad:
-The stock standoffs are too short, you could probably get away with 30-32mm standoffs but it would be tight, 35mm standoffs make it very spacious.
-If you use the Brain3D DJI antenna mounts, MAKE SURE YOU SECURE THEM so they cannot slide very far up or down. My first crash with this quad caused the top antenna holder to slide all the way down, the force bent the MMCX connector to the point it was unusable. I used a couple of RDQ 45° antenna tube mounts in between the two antennas to keep them from being able to slide too far.

One day I'll come up with a better solution, but for now it has survived multiple crashes like this just fine.
-If you want to build this system on 6s, you cannot power the Air Unit directly off battery voltage. Thankfully this FC comes with an 8v/2A regulator which has worked perfectly so far. T-Motor has a couple ESCs with 10v regulators, so you can really use any FC you want, I'm just partial to Aikon ESCs.

This looks tighter than it is, the air unit just barely contacts the R-XSR, and it makes for a perfect spot to secure the excess camera cable.

Definitely the heaviest racer I've ever built, but HD FPV is something to behold, it has ruined analog for me!

610g AUW, but it really doesn't feel that heavy in the air. I can get 3+ mintues of racing out of it no problem.

How it compares to my two favorite analog racers. I really should make pages for these two.

Alright now for the details for anyone who cares:
-Frame: I went with the Source Two because it's cheap, spacious enough, and durable. Whenever I build another of these I will probably try a different frame.
-Motors: I normally use F60 Pro II 1750kV motors for race builds, but I wanted more low end power. I figured it would help with the added weight. 2020kV is a little high for my taste, but with the throttle capped at 85% they feel very similar to what I'm used to. I've ran the quad at full throttle and had no issues.
-ESC: I've owned three Aikon Ak32's (two of which are ~2 years old), and I've never had a single issue. Figured I'd try their new flagship ESC and it does not disappoint. barely warm after a hard flight.
-FC: The only FC I've found so far that is plug-and-play with the DJI Air Unit, and it has plenty of other cool features aswell.
-Camera/antenna mounts: The mounts that come with the frame will work for the camera, but I don't trust them as they are just thin pieces of rubber. The manual for the air unit says to mount the antennas 90° to each other and at least 40mm apart. None of the other mounts I've found can achieve this.

I run the air unit at 700mW, low latency mode, 4:3 mode, with focus mode turned off and I've had no noticeable latency while racing. I've haven't done any longer range testing as I'm not much of a freestyle pilot. I plan to test it on 25mW in the near future. If you have any questions feel free to ask!