Which upgrade if any?

To start I'd like to say I don't necessarily know what I like in a pair of headphones other than being open-back as I've never really had an excellent pair so I've not got the best idea of what I'd appreciate, I just want something more clear and less muddy.

I currently own a pair of Sennheiser 559s which I've enjoyed but they are getting old and their audio quality is not the best.

I've seen 2 headphones on sale for Black Friday, the Sennheiser 599 SE (£69) and the Philips fidelio X2HR (£67)

So I'm wondering if either those headphones are a large enough gap in quality that it's worth upgrading and if so which one of the 2 should I pick?

Thank you in advance.