I voted for Server 4. Reasons:
1) Same as YorVeX's argument: simply because none of us admins regularly plays there and it's our only winter server.
2) It's interesting to test new settings in a rough competition.
3) IMHO, medium goal servers are perfect for such tournaments:
a. It's not that long as our Long-run server, so players won't be that tired & AFK
b. It's not that short, so lucky start doesn't matter that much, everyone have the time to catch up.