In reply to nutme:
In my experience the durability of skinny ropes comes down almost entirely to how they are used. If it's for onsighting and the occasional redpoint it'll last a good long while, if it's used for dogging + working routes it won't last all that long. Smooth limestone is also guaranteed to give it a bit more life, whereas harsh granite will undoubtedly wear it a lot, lot faster. I wrote off a single 8.9mm whilst doing the American Direct on the West Face of the Petit Dru, but it did get a battering from a great many pitches, a lot of harsh granite, a load of abseils, getting stuck in a couple of the aforementioned abseils, and so on and so forth. Still, it made for a quite expensive outing!
Hope that's of help.