I have bought this. Not the "kitchen sink" package, but just the 3-antenna upgrade package for the Mavic Pro. I've had a chance to use them for a bit and here are my thoughts.
The antennas do not look as sleek and glossy as they do on the web page. The base and some parts of the antennas are 3D printed, giving them that ripply look. The mill-work is a bit rough, also. The web site bills them as being "hot swap-able in seconds!". First of all, I don't know why anyone would WANT to switch antennas mid-flight, but ok... Secondly, the antennas come with a sticker specifically warning AGAINST taking the antenna off while the controller is powered up or "severe damage may result." So yeah, I guess they are hot swap-able in seconds, if you are willing to power off the controller then spend many many seconds swapping out, then power the controller back up.
Thats all well and good, but "HOW DO THEY WORK?", you ask. A fair question, and the only one that is really important. I don't have much to say about the 360^ antenna. It seems to work just fine at close range without needing to point the controller at the drone.
With the stock antennas, I could fly my Mavic at a height of 30m (100ft) to a distance of 560m (1/3mile) before I lost the signal. This is in a moderately forested suburban environment. If I increased the height to 40m I could gain a little more distance.
The 45^ antenna is advertised as "virtually guaranteed HD signal" and a range of 3-4 miles. Now I'm not a photographer or videographer and I know nothing about those subjects. I just use my smartphone screen to see where I'm going. I've never tried using a tablet in-flight. That said, I experienced NO improvement in distance with the 45^ antenna over stock. 3-4 miles? HA! On a flat, open plain, maybe. I have no idea. As to the HD signal, I can't really say. Thats not something I use when I fly, since I'm not doing this for the photography.
The 90^ "distance" antenna was the one I was really interested in, and after testing the other two briefly for this review, is the only one I've used. It is advertised as being able to go 4-6 miles. I've never tried it in a flat open desert, but I don't believe it for a second. In my home environment, at the stock-test altitude, I was able to travel 715m (.44miles) before losing the signal completely. So I got about a 10% range extension over stock. Again, if I increased altitude to 40m I did gain a little more distance.
I have no complaints about the service at Drone-World. As advertised, they did the install themselves with no hassle. I had my controller back in a week, ready to go.
Overall, at a price of $349 I would not buy this package again. I only bought it because I didn't see an option to ONLY buy the 90^ antenna upgrade. If they offered that at a $300 price point, I "might" still buy it, if I had it to do over again. At $200 I definitely would.