I had a MV Minecon cape, but as soon as I changed my cape, it said "I have to Contact an Admin" Because it failed or something. But like he said, it's a new plugin, and still some bugs.
What happens if you already have purchase an optifine cape, and would like theses ones, would that mean paying again?
I think that the capes were a wonderful idea! And the new background looks absolutely AMAZING, and supports "Mineverse".
Because they are like ranks- They are cool and help the server keep on running. They aren't too expensive because of the fact they don't really give you perks, just popularity.