While I certainly agree that following the leader is generally good advice, when someone tells other people how they should be playing, it rarely goes over well.
Instanced or not, I really appreciate the folks who give up their time to host regular MSRs for people.
As for which is better, for my part, I dread the green button, because on at least two occasions, I got very poorly-timed baby aggro and missed out. I don't like being that guy. If instanced had trainers, that would be awesome.
I played with Plas quite a bit on live, and even met him (and his Dad, who wore a nametag that said "Plas' Dad") at a Herocon event. He was a very kind soul.