good question.
I also have sites with LMS/BACK LMS and sites with VRRP MASTER/STANDBY MASTER.
both methods are really good for fast hopping from controller to controller during a failover in the master.
THE VRRP method much easier from the AP side (because the AP connect to only 1 address)..
but i would like to hear also , which method is better,and of course why?