The feel from the battles is very different in MoM and FE indeed (playing the beta made me want to reload MoM, so it is a quite refreshed experience) :
As other have pointed, in MoM, it does take longer to reach the ennemy indeed, unless you are used heroes stacked with + Mv items
MoM does count 1.5 Move for diagonals, unlike FE
MoM has a few terrain features.
FE has Zons of Control, which is cool. I wish they costed more to exit, and did not only force you to stop your move when going from Zoc to Zoc.
MoM had many more spells to cast during combat, so there was more variety and more decisions to take.
Diagonal attacks (I know, they were in MoM too, but that's not a reason to have them in FE) are one of the reason it is so hard to balance heroes vs troops :
If you could only attack the unit facing you, you could use cannon fodder to protect the flanks of your heroes when they do the hard work. Now, with diagonal attacks, it is kind of pointless, as they can still be attacked by 3 units. with diagonal attacks removed (or restricted), you could effectively protect valuable units much better, and there would be more point to the tactical battles, because you would need to flank the opponent to gang up on him.
I strongly agree about movement needing to be toned down, especially with the initiative system allowing a unit to move several times in a row.
Army setup would be nice too indeed, but if units can still zip around the map so quickly, it will be kind of semi pointless.