Hello,
I would like it if there was a speed server every third month. On the speed server you would be able to earn trophies that come back to your main character such as Third or Fourth in Herocon for your team.
On the speed server you could also have a random old Season listed as a way to get the previous seasons outfits and pets. (this would make money for HZ and justify the server)
On the speed server you could create a special event or scavenger hunt that is only on the speed server and brings back rewards and heroic deeds back to our main server/character.
On the speed server there could be special pets earned at certain levels that are unique to the server.