I might be willing to try these, they seem quite well made by all accounts.
Drone World
the problem is the price compared to stock props, and even then the advertising is pushing the limits of my BS test - they're both stiffer than stock, but retain flex for safety?
props are realistically only likely to be damaged by hitting something with them, and if I do that they're getting replaced, end of story - and I'd rather replace stock props then worry about not doing so with these for the price. it's too expensive an aircraft to fret over a few dollars on props.
Recently got a set also, and they do exactly what I expected them to do. A noticeable decrease in sound, and just a bit less responsive than the pro props. I’m happy with the purchase
the problem with the "decrease in sound" issue is that as a rule of thumb, you need -10dB change to perceive the noise as half as loud. as a telecommunications engineer, 10dB is a massive step.
noise also radiates in three dimensions, so it is subject to the square-cube law. that means that doubling the distance cuts the apparent noise by 6dB.
in
this video, the results were:
standard props
84dB at 2ft and 58dB at 30ft distance.
platinum props
79dB at 2ft and 55dB at 30ft distance.
that's not bad at all actually, but then you do have to bear in mind that the standard props have already dropped to platinum noise levels by moving from 2ft to 4ft (i.e. not a real world operating distance), and 55dB is about the amplitude of elevator music. that's going to all but imperceptible outside, and even then you need to be 10 yards away for that to occur.
I also know a bit about aerodynamics, and the decreased response of the swept tip props doesn't surprise me at all. there is rarely anything free in physics (if so, you just weren't using it in the first place), energy doesn't just go away, and less noise means less air moved at the squared tip of the regular props - right where they are most efficient.
so ultimately if you want to use the platinum props by all means do so, but I can't see how they represent a real-world improvement over the standard ones if you already have a few sets.