The ultimate shape-shifter quad. This is my do-everything filming rig.

This is where I wound up after trying a lot of different frames as my answer for being able to film with the most versatility for chase footage, race footage, and mid-range cruising. The similarity to my Neutron-R race builds is carried forward, as is my proclivity for running budget parts where I can't fell a performance difference - this has the bling where it counts. This also takes advantage of what I've learned about using props and batteries to add significant amounts of flexibility to setups. The 6" frame means I can use TM6143 props on 4S and cruise for a really long time elegantly, or slap on 6S batteries and run GF51433's and be at DJI race pace despite the extra weight.

Frame is a FPV Flight-Club Proton-R. This is the same architecture I know and love, but has the 30x30 mounting that gives me more confidence for pushing harder or going long range.
Motors are AMAX Inno 2207 1950KV motors. These came from RDQ Clearance at less than $11 each... but they are amazing motors for performance. The Performante motors are remarkably light and perform amazingly - principal drawback is the durability of the shaft-bell interface, as these can be slightly fragile, but this quad isn't really intended as a crasher.
Stack is a Racerstar F7 Lite stack. It sounds crazy to run such a cheap FC, but honestly for easy installation with a DJI air unit, this has been the best unit I've found. Performance with the MPU6000 gyro has been exceptional, and with this frame I have a dialed multi-cell tune ready to drop in from my racers, and if flies absolutely dialed in.
Tune I have a Betaflight tune for my racers, that I use on this with slight modification. To achieve that, Irun everything at 48kHz PWM, 23° timing, 0.25 rampup power, and demag comp on low. I run BF4.3 with sliders at:
Master 1.1, PD Balance 1.2, P&D Gain 1.4, and FF 2.0, using DMinGain of 33 and DMinAdvance of 0.
I try to disable gyro lowpass filtering and, run aggressive DTerm DLPF filtering (biquad at 1.4, dTermDLPF_Expo=10 - this is aggressive, not recommended), otherwise running the tuning notes suggestions for dynamic notch and enabling yaw LPF.
Upcoming Betaflight releases will have a 'Tehllama Tune' features most of this preset with filtering customized for these motor/prop combinations.
FPV Gear is just a DJI Air unit and 45° fixed mount. The air unit is a huge part of why this setup is so versatile, especially for mid-range and poor RF areas. The fixed 45° mount and lots of field of view from the DJI camera means I can actually fly smoothly and slowly at low angles, or run this at full potato race mode without changing anything. Using the integral antenna mounts from FPV-FlightClub make for a really easy setup (slight headache fitting the DJI antennas, but they're super well protected).
RC Gear is TBS Crossfire, because it outranges DJI, and with CRSF-Shot and locked 50Hz modes, this can run like a racing quad, or be ran like a long range quad from the same hardware effortlessly. Link quality remains in the 90's at the point where DJI starts dropping bitrate, which is well beyond the range I'm willing to walk, and more than adequate for filming opportunities I've had so far.
I've also added a cheap BN-220 GPS unit, primarily for running GPS.lua, and using the limited GPS RTH capability, mostly to pop up and regain some flight control should I lose RC connection.
Props are part of how I manage the mid KV rigs. Gemfan 51433, HQ 5.1x3.6x3, and DAL T5040C props all work well on 6S setups. For 5S 1300mAh Black Series packs, this thing is actually at its most versatile, it can chase cars for 5 minutes, or cruise for 7 minutes. GF 51466 and TM5146 props are my favorite in that configuration. On 4S, I like the same 51466 props, and can use up my 51499 and DAL T5050C props as well. The proximity capability on 4S with the 51433 props has been able to delay any desire I have for a ducted quad, because this is so controllable, even at lost speed.
The other added capability is running larger props, since this is a 6" frame. The same recommendation I have been giving people for years, this captures - build a 6" frame with 6S electronics (in this case with a BEC for the Air Unit also) in mid-KV (1900-2150KV). I can also run GF5552 5.5" props for high speed cruising, or TMotor 6143 props for very efficient 6" cruising and chasing. The higher cruising speeds of the larger props coupled with otherwise race quad AUW really make the versatility obvious.
Batteries in this case are primarily CNHL units because price. The weight and performance of the black series is phenomenal, although I still use a lot of the older 100C G+ (White Series) packs because of insane value that I'm willing to punish them hard.

Overall, the 5S 1300mAh packs paired with GF51466 props are actually my favorite with this setup - but it can do so much more

For a one-quad quiver, this is hard to beat

If there is a more complete answer to what one quadcopter you'd always want in a backpack for outdoor flying, I'd love to hear it. Other frame options can achieve the same thing, different stacks will work just as well, and other stout motors in the same KV range can also deliver great results, but the overall formula is what I honestly believe should be the standard. New frames with integral DJI support can also be used for this, but I still strongly recommend building them as 6" frames with mid-KV motors to unlock the full potential.
It just does everything you can want it to for a DJI quad, and does it extremely well.