Graphically, it's not bad, it's just that it seemed like a step down from sprites.
Story-wise, the game is pretty bland.
Characters are not all that interesting.
Gameplay is kinda killed by the fact that there are so many choke-points and it's easy to stall your way to victory with just one high-def character.
FE12 fixed a lot of things, though. My favorite game in the series.
FE11 wasn't bad in and of itself. It just wasn't good either.
The gaiden requirements were more of a complaint for the series veterans, imo, since newcomers either got them by being bad or didn't know about them.
I do agree that whole "less than 15 units by X chapter" was BS, though.