Like I said, at that price point its not necessarily better, but a side grade or different sound in that mid fi group. A real upgrade might be going to a crack/Senn 650 for example.
Philips X1
- strong bass/elevated bass
- slightly more laid back mids
- very slight treble bump, rarely noticeable imo
- moderate soundstage size
- overall a slightly darker and more fun/head bopping sound
- much better build quality imo
Q701
- weaker/less extended bass - has a mod to rectify somewhat - will not be as strong as the X1 though
- very detailed and complete mids - somewhat thin sounding to my ears at times, but some prefer them over my type of SS
- large soundstage, but still not the biggest around
- very high detail level, seems more detailed than the X1
- brighter sound and more prominent treble
- a bit more plasticy than the X1 in terms of build
Both were very comfortable when I tried them.
I think the Q701 would be a fantastic complimentary can to the X1 as they both sound different and can provide great quality for different genres.