I've played and beaten the three GBA titles, can't say the same for the NES and SNES games. Not sure how you could describe Radiant Dawn's difficulty as "lol" compared to the GBA games. Story- and characterwise Fire Emblem 9/10 bests Fire Emblem 6/7, Sacred Stones anyway.

I personally enjoyed Sacred stones the best mainly because of the branching campaign and the world map. I personally do not find Radiant Dawn that hard because you can save after every move. Also, Mia would get destroyed by Edward. Just sayin' :P

The hard save feature is disabled on hard mode as well as the weapon triangle and additionally the movement ranges of enemies aren't displayed anymore. The people who claim that RD isn't that hard usually haven't played it on hard mode, just like the people who keep saying that Edward destroys Mia. Bringing Edward to an adequate level in hard mode is a lot of work that doesn't really pay off, because having a good Jill for the desert chapter is more useful than a good endgame Edward. With Mia you don't have to go through such troubles and she always ends up with rock solid stats.

Meaningless? Are you nuts?

The character who holds the advantage gets 1 attack and an accuracy bonus while it is the exact opposite for the other character. You just have the play the prologue of Radiant Dawn on normal and hard to see the difference. On normal, the enemies have a hit percentage of about 40 while on hard it goes up to 70. Considering how fragile Edward is, the prologue is no walk in the park anymore and you probably have to heal him several times.

Shortly afterwards Nolan joins your party with his steel axe, a weapon with rather low accuracy by default. Without the weapon triangle, it's quite common to see lance users having higher accuracy when fighting against Nolan. A low bio rhythm only makes matters worse.