Chiming in a bit late here, but I too have always heard nothing but nice things about mealys. They aren't terribly popular in the US, but they apparently are just as gentle as small amazon species. "Gentle giants" is the most common description I've heard about them.
It's those hot-3 amazons (YNA, DYH and BFA's) that give all amazons a "bad reputation". Smaller amazons and mealys are all known for actually being pretty nice, gentle, loving birds who don't typically experience severe hormonal issues/aggression. Unfortunately, since none of the other amazon species ever became quite as popular as the 'hot 3', most people just kind of lump them in behaviorally with their naughty cousins, which really isn't fair to them. I grew up with a GCA and a DYH and of course have my BFA. The GCA was like a whole other species to the DYH and BFA. Very calm, gentle, never bit, would step up to anyone just about the nicest bird you could ever ask for. Mealys have a similar personality to my understanding. I wouldn't be "afraid" of a mealy at all!
I love these kinds of threads that keep you checking back.
Mine has no yellow at all. Other subspecies can have it or not as far as I know. 
