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!