It's hard to say.. I use the "T" rubber that Sorbo makes in my Sorbo channels.. But I bought of box of Soren Ettore "T" rubbers this last go and I have to say that I think the Sorbo rubbers last longer.. Also, the Sorbo rubers seem to preform better for me. But it might all just be in my head or it could be that I just got use to the subtleties of the Sorbo rubbers and just altered my technique to them.. But I have decided going forward that I'm going to stick with the Sorbo rubbers for my wide body Cobra's and Quicksilvers..
On another note, the Sorbo jam-proof end tips have gone down hill.. I had those exclusively on all my poles for a long time.. Just recently (this past year), I have broken 4 of them.. Those tips have never broke on me before.. I admit I put a lot of pressure on them when doing strait pulls, but no more or less then I always have.. I think they are being produced with cheaper composite plastics now... Also, tools are getting jammed on them now and they never did before.. So, I'm already into a new solution for pole tips now.. But I was disappointed that Sorbo cheapened up those tips.. Hopefully he won't do the same with his rubbers..