Strat isn't power metal. Well... I mean, I guess they are, but they're kind of a horrible offshoot: "virtuoso metal", I guess I would call it. I used to have a number of albums from bands like that back in the day... I hated all of them (not sure why I got them in the first place). Rhapsody, Strat, and a few others I can't remember. Horrid stuff. But most powermetal fans will be quick to disassociate themselves with those.
The cornerstone powermetal bands are probably Iron Maiden, Helloween, and Iced Earth, along with a lot of bands that are now classified as prog (Symphony X, Fates Warning, to name a few). Obviously, there's a fine line with powermetal into complete and utter cheeseball rock. Quite a few powermetal bands cross into that, but the good ones are able to mostly stay away from it.
I guess the definition of powermetal are things that would probably be considered, by today's standards "hard rock". It's more a direct descendant of the old 1970s metal bands like Sabbath and Deep Purple. It's dramatic, often pretty "fun", and tends to stay away from personal angsting.
I really feel that if you're going to be that angry sounding, it should be done with a large grain of salt. Power Metal bands are all about over-the-top drama, where-as I think thrash bands really get caught up in actually being aggressive and angry, at least it sounds like it to me.
Anger and aggression can be a fun means to high energy, but at the end of the day, it's really hard to believe that it's REAL, there-for I prefer a large dose of "nudge nudge, wink wink" with my metal. Devy and Maiden offer that in spades, which is why I love both, even if they're really different.