I use failover pools as I don't see the point for using loadbalancing pools unless a download manager is in play.
I've created two failover pools (WAN2 has a faster download than WAN)
WAN2FailsToWAN Using a port alias with http https etc. (80, 443, 6667, 1935, 25, 143, 465, 993, 587)
WANFailsToWAN2 Doing everything else.
And another question, is there a way to add a hostname to an alias instead of an IP? (so that the firewall would do the resolving).