Shh! Don't tell him that before after he's gone through hell! On my first Hard playthrough, I was owned like hell on 4th and 5th floor. Now that I knew it, it wasn't that hard.
Still, the final boss of FE10 (no spoilers) is very hard, and definitely the hardest among the series.
On a semi-related note, I'm playing Advance Wars (1) for the first time now. I played the latest one on DS, but it was rather dissapointing. This one (1), however is a lot of fun. Well, untill the CO-powers started for real at least...
When I write Fact: in one part of the post, and opinion: (or a similar word), it's not because I can then say "my opinion can't be wrong". It is to inform what part is pure facts, and which part I try to draw a conclusion in.