Top Audiophile Ethernet Cables - any comparisons?


I just set up my new streamer with which I stream music from my mac mini to my dac. I use a dedicated network switch which connects the streamer and mac mini directly without going through the rest of my LAN.
I exchanged a standard CAT 7 cable on one leg of the connection with Audioquest's Forest Ethernet cable. There was a small but clearly audible improvement. From the reviews on the Web I conclude that the top cable by Audioquest (Diamond) would give the biggest improvement of all Audioquest Ethernet cables. 

Now my question: Has anyone compared the Audioquest Diamond with any other top cable by another manufacturer, e.g. Purist Audio, Cardas, Chord, ...? I live in Switzerland and have no dealer who can give me several of those cables to try. Thus, before spending a lot of money, I'd like to hear any opinions.

Thanks a lot for any replies!

By the way, I use a network switch that was modified for audiophile purposes (AQVOX). The difference to an off-the-shelf switch is tremendous!
belcantor
I'll be going out to WGUtz's on the 11th with managed L3 switch. I have ports 7/8 in a LAG that will allow for one generic and one 'audiophile' Ethernet cable to be swapped without his knowing what is in use.

Will follow up after with listening impressions and whether or not they track with the cable in use. 
@david_ten: Thanks for the most helpful link - haven't found that site yet!

@willemj: Thanks for the link. Despite the theoretical considerations I did hear a difference between the two cables I was trying out. Measurements only help if they measure the relevant things.

@jinjuku: A lot of people (including me) would be grateful if you will share the results of your blind test.
Cables that I've had:

Audioquest Vodka 1 meter $340 ($82.5 / foot)
WireWorld Starlight 3 meter $340 ($27.5 / foot)
Nordost Heimdall II 1 meter at $700 ($233 / foot)
Berktek Hyper 5e    98 meter at $90 ($0.30 / foot)

Differences that anyone could hear: 0