Never liked 40-man raiding. It turned into a full time job, grinding resources for potions/flasks, grinding for gear, waiting for raid setup, waiting for that one jackass who had to take a crap just before the first pull, the 20 minute explanation of simple fights for the numbnuts who didn't read up on the boss.
I much preferred when they started introducing 10-man specific raids, then eventually the option to do 10/25-man raids in all new raid instances.