I am a little wary of the 325e given that some found its predecessors bright. It's said that the 325 was always the brightest of the Prestige Series. However it always reviewed well and the 325e is appreciated pretty much across the board.
It does sometimes seem a little odd to use metal casings for acoustic properties. (Yet there is an award winning new £60 Sony earphone that uses brass.) Some say the 325 sounds a little metallic, but I am all for giving it a chance. I wonder though if wood cups on my 225e would be better than 325e. (In either mahogany or maple as Grado have used). I have been looking at the hole-boring drill bits that I would need, and I think it can be done. Considering the cost and effort though I understand why people buy ready made cups, or higher end Grados.