Take Astra and Aether for example.
In FE9, Astra was a 5-hit, rapid attack at half damage each. It was quick.
In FE10, Astra was... well, it's at normal damage, but you just stop when you killed the enemy.
In FE9, Aether was a badass, throw-sword-in-the-air-and-land-and-do-lots-of-damage-pie kinda thing. With the flipping and whatnot.
In FE10, the same effect applies... but it felt slower, while Aether was faster-- and sometimes, Ike might only do one half of the Aether, and... that's it.
Sol was a yellow glow in FE9, and the horse neighs, and you strike. Simple.
Now, it's just two strikes, a neigh, and another.
Gah. I miss the old Aether... sure, Radiant Dawn's graphics are awesome, but there's no blue-aura, the flipping and camera shooting Ike in the air... and I remember all of the sounds. SHING! Whoopwhoopwhoopwhoopwhoop... daTISH, TISH!
Edit : Of course, I know graphics and the sounds don't affect how much damage and blah blah blah, but I liked how they looked. And now, they just look meh.
Say, I've only played FE6-10.
Were skills in other games?