If it's the best sound that your thinking of, then a general consensus on this board is that you'll get best improvements by concentrating on speakers. From what I understand apodising isn't seen as a significant upgrade when compared to jumping up a level on the speaker front.

Cheers
Tom

Main: G61SL, 218, HD621, 2*7200SE, 7200HCSE, M6s, DSW, Apple TV 4K, NUC (Roon server)
Secondary: Wiim Pro, 3200, Audio Core 200
F80