It is never fast enough.
A buddy of mine is considering moving to Murfreesboro where I live. He unfortunately is looking at a side of town he can only get DSL from Bellsouth not Comcast cable which as a rule tends to be faster. He went and found Linksys makes a router that has TWO wan ports and you can even load balance between them. Of course he wants to bond two DSL circuits with the thing. You of course can set the ports up for failover. But you can never have it fast enough so why wouldn’t you bond it with load balancing?