Just letting you know that I tried this in the lower cage of a P183 with an F3 and an F2 green.
First with a 3mm non elastic cord, like this:
And then with a 3mm bungee/shock cord:
The result: I cannot say with confidence that I notice a difference. This is probably also in part due to the silicon grommets between the cord and the metal casing, as you can see in the pictures. If I had to take a pick, I'd say that the elastic method is slightly better, but honestly it could as well be placebo.
They did both seem to be an improvement over the default mounting, tho. But not a big improvement, the default mounting is pretty good and should be fine for most people. But in my case, the HDDs are definitely the loudest components, since the fans are inaudible in idle.
I think to reach a definitive conclusion on acoustic properties of non-elastic cord suspension, we'd have to try it in more problematic cases, where any kind of suspension makes a big difference. The P183 is not such a case.