I made the move from Wax bi-wires to Ibis singles with jumpers. I will say one thing - they take freaking forever to break-in!!! Are they worth the jump - hard to say. I took the leap because I got more for my Wax than I paid and piggybacked it on a Zu 25% sale so my net cost was palatable - especially in my lowly "Canuck bucks". I still haven't decided if silver is better than copper in my system but I can say that the Ibis are a transparent cable and hide nothing. I can see how a tube system would benefit from their introduction but only after a lengthy time in place.
While I haven't been around this new forum and HD as long as most of you people its my impression that most participants are looking for the best value and that might lean more to the side of inexpensive as opposed to products on the pricier side of things. In other words if the Ibis at $1200 "were" the equivalent of another manufacturer's $2500 cable they would be a good value but yet still perceived as expensive to many of the participants here. I think more people here might want to pay about half of that and invest the remainder in upgrading one of their components - but thats just my take and I could be quite far off the mark...
Summarizing, the boys at Zu are great to deal with and offer good value in all of their products - one's own pocket depth will be deciding factor if the Ibis are worth the jump over the Wax...