I this case it just means that these are fine headphones but poor value since you can get this level of performance elsewhere for less. Nothing new though since to me all Sennheiser's are poor value, save for the HD580.
The Stax Omegas are a faithful representation of what you feed them so in effect nothing special. Both the SR-Omega and SR-007Mk2/A add a little bit of color, each in their own way, but the phones are essentially devoid of colorations. This is what I listen to every day and the HD800 doesn't come close, far too colored. It isn't a bad effect though if you are into that kind of sound.
The wow factor can be very misleading and is often why people choose MP3's over lossless encoders as the MP3 isn't as linear and can be "impressive". Aside from the soundstage the HD800 isn't impressive so that might be why they fell out of favor so quickly.