Senn HD660s compared to Audiofly af180

I currently own Audiofly af180’s, and am looking at purchasing a pair of HD660s. How does the sound compare between these two?

I’ll be running them from my Fiio E10k and LG v30. Would a new dac/amp make much of a difference?

Also, I’ll be getting them for $295USD. Is this a good price?

Cheers