They both get really good write ups so choosing between the two would be a case of trying each and deciding on the sound signature/comfort levels.
From a personal perspective i've always favoured Sennheiser HD-25's and in the last 6 months i bought myself a pair of their uprated HD-25's called the Amperior, it's similar in style to the HD-25's but the ear cups are milled aluminium and the cable is different along with specifically tuned drivers in the ear cups. They offer excellent isolation from outside noise and the sound is quality is up there with the best, you'd have to spend serious money to better them - I use them straight out of my iPhone 5s and out of my macbook with a dragonfly dac, or at home out of my Audio Kontrol audio interface.
For years i've had a bad habit of headphone geekery but i've pretty much only listened to my Amperiors since i bought them to the extent that i've sold 3 pairs of my other headphones recently as i never used them, B&W P3's, Grado SR 325, Sennheiser HD-25 mk11.
The Amperiors sometimes come up under £150 so it may be worth a look but any of your two choices will sound good.