Yeah I need more than a couple of hours on them, it's very easy to say something sounds wrong when you're conditioned to a particular headphone.
I did try the K702's a few years ago but found them very uncomfortable, hard to drive and genre limited. After paying a hefty re-stocking fee (not used to that in the UK) I returned them. A few months later I took a punt on the Shure 1440's and have been pleased with them but they need more low end punch for a lot of recordings.
Must admit I still find myself using my ancient Sennheiser 590's from time to time (15 years?). They sound like trash for a couple of minutes as the mid-range is so recessed but they're so comfy and an easy listen.
The X2's could still go back as Philips have a 28 day return policy but I'm definitely going to give them a fair chance.
Other cans on the shortlist... PM3,
MDR-Z7, Audioquest Nighthawk, Audeze EL-8 (open or closed). If only I could try them all...
I don't think I can bring myself to buy the HD600, all the owners sound content but want something more