I've done some listening of HD700 in comparison to other Senns like HD600. There was one thing that I spotted at the very beginning, that the HD700 sound like loudspeakers, i.e. there is no left and no right, but rather left front and right front. It was an interesting experience, however I'm not sure if this is what I would like headphones to do. Other very significant and easy to spot thing was level of detail. While HD600 would beat everything else they had in shop, the HD700 IMHO beats HD600. I love the way HD600 sound. I had opportunity to audition them twice, and I really loved their sound. But if I were to be objective I must say HD700 definitely sound cleaner. I didn't compare directly Alpha Dogs with HD700 nor with HD600, but I have quite good memory of how they sounded, and I think Alpha Dog present almost the same detail as HD700, were HD700 is just a bit better. What I really didn't like about HD700 was that I found them extremely boring, especially this placement of sound few meters in front of me. I was thinking, how would these headphones work in Counter Strike? How would I hear sound from the back if all sounds are in front! I own one headphone (RH-A30) where drivers are slightly rotated so sound is little in front, and I really prefer to use Alpha Dog with Counter Strike, because I can honestly hear sound coming from back. On the other hand I find RH-A30 more engaging, but I can't say that about HD700 - for me they are boring as h***. Interesting is that the next headphone I really think of buying now is HD600. I really loved their sound.
Recently I'm listening lots of stuff on Spotify, and I found that sound quality is very poor, even with Premium account. With RH-A30 (on Alpha Pads) Spotify rocks (especially EDM), but with Alpha Dog it really s****. I downloaded recently Sibelius Violin Concerto from HDTracks in 44/16 and I found it on Spotify as well. If I play on Roland or loudspeakers I wouldn't notice difference, but on Alpha Dog it's night and day. So here is my advice: when you're buying expensive headphones you need to have collection of high quality music, otherwise you won't have things to listen to.