I like starting fresh with each class and would like more character slots.
You can have up to 5 different characters per server in a same account, so you’d only need to choose a different server and would have 5 more slots. There are only 9 different classes now, with the Warlock coming next summer that will make 10 classes, so 2 servers are enough to have 10 characters in the same account, one from each class..
Adding to Fernando:
If you want to play on the same clan/group.. join in the cluster. Benefit of merged servers
Else just choose and a new server and get grinding