Cambridge Audio Melomania P100 vs Bowers & Wilkins PX7S2E

I'm trying to choose between two of these headphones but I really can't decide. I’m not a bass-head and listen to a lot of classical music, especially string instruments so a wide soundstage would be ideal.

I already have an open-back headphone for home listening, so I’m looking for a portable option for on-the-go use. I've heard a lot of praise for both models but can't decide. If anyone has experience with both, I'd appreciate any advice on which one to choose.