Just on the GUI. If it is custom coded what you could do it bring back the icons however when a trail is selected the item in the gui has the enchanted animation. It it better than all grey dye and much prettier.

Also when player are still too long the particles turn off. If its on purpose, it is really annoying xD

 

If you think about a rank like donor10 which had nothing more than a couple of extra commands, a kit, and a pet chicken you can see where others may disagree. You are adding actual things that you can show off because you are a donor.
Since the addition of trails and disguises donor10's now have more perks to make the rank worthwhile.

When I was a donor10 I just wanted to get to donor25. While I enjoyed just having mob arena god class access and being seen easier in chat it was lacking in perks that made me want to stay donor10. Now I am a donor400 and I have a donor10 account and when on that account it feels a little more fun to be on simply by messing around with trails and disguises. I didn't feel like "urgh this rank is so inferior to what I have now". Even if it has far less perks.

So its all well and good that this is not a selling point for you. But for people who are trying to get the most for their money, don't have a lot to spend on a rank, and those who just want to get into the donor world it is less likely that they will pass it up because there are not enough perks.
Visual perks still sell and looking at some of the larger networks that have switched to Eula friendly it is evident it does. Yes, sales help but generally people still use real money on it and still consider it worthwhile.