what copper plugs are we talking about with the Mobius? i'm pretty sure that the little plugs on the left and right sides were a silver colour...of course that doesn't mean they aren't copper?? are they really copper, and why would they use copper and not some other higher quality metal...like the beautiful aluminum that lies at the base of the little plugs?
xaipemw,
yes there surely is some cons regarding the Mobius. but i feel they are well worth it to have such wonderful, beautiful, essentially perfect sound. i'd also like to point out that there are cons with every cable one can buy. nothing is perfect, except for the Zu's perfect sound

one just has to find which cons/cable combo they are willing to live with.
some things i don't like about the Zu's are...
the cord is a little stiff, although not that bad. it is somewhere in between an extremely stiff cable and a flexible one (650 stock cable). and it breaks in after awhile too. you also easily learn how to adjust. the issue of the Mobius being stiff is something we all must deal with anyways when upgrading to any of the thick, high quality cables (although i think some of the others are a little less stiff, but not by much). another thing i disslike (perhaps my biggest gripe) is the fit of the plugs into the Senns. it is exetremly hard to do! once they're in, boy are they in there for good. but in the end, all it takes is some pushing, time, and patience to get them in. i personally didn't need to use any sort of pliers to get them in...so it is possible to get them in without the use of a tool. on a positive note, after they are installed, the tight fit provides for a VERY secure fit preventing them from being yanked out as easily as some of the other cables. the length you pay for i also think is a little poor. too short for too much money. but my amp can be easily moved around by the length of its cord, so it really doesn't matter to me. the only reason i bought the Zu's was because i sold my HD600's to fund them. but again, in my view, the pros far outwiegh the cons by a LONG SHOT! plus, the return policy is great for just being able to test them out without worrying about money issues. as far as cables go, they are the best looking, imo, of them all and perfectly match with the HD650's silver/greyish colour...Zu must haved planed it this way

so, in the end, if the worst thing one has to deal with when owning the Mobius upgrade cable is the tight fit of the L&R plugs, then they are well worth their hefty price tag...again, imo! it is a very
small price to pay for having pretty much one of the best sounding headphones in the price category.