To my mind the 8s justify the price, and I am forever thankful that high end audio is not a mainstream thing, for the price would most likely appreciate all the more. Four years of engineering went into them, after all.
I only have the hunch that the DX50, even after Rockboxing it, is not equal to the tasks demanded by the 8s. Already Truckdriver bought a DX90 and immediately sent it back from whence it came. In spite of its warmth I will be going in for the AK120,next month, which I may then have modded by Red Wine Audio. Apple need to look toward these things now, if not six a long time ago. They coulda, shoulda but wouldna even so much as up the iPhone to 128GB.
Unless you are looking for a used AK120 it might be tough to find them in the future... At least I know looking online at Canadian retailers most shops have now changed out to the AK120ii.. I found 1 place still selling the AK120 and it is the in store demo. YMMV on find one though