Love these ropes, very light, and resist snarling better than other skinny ropes in my experience (they are still a pain in comparison to a fat rope, of course). Due to the lightness they're obviously not as durable as heavier ropes. Used for multipitch ice and rock.
Peter, I and other partners all own a pair of these and all abuse the hell out of them, 24/7, all seasons in the Canadian Rockies, rock and ice. I have switched to Beal Ice Lines for ice, but Phoenix are my recommendation for your primary doubles.
My experience with these ropes have been less than positive. I have always climbed on two ropes and for 20 plus years, I used BEAL 8.5 mm, 50 m doubles. I bought these Phoenix (60m) couple years ago and I think next time I will go right back to BEAL. These ropes kink way too much and repeated attempts to fix the kinking go nowhere. Just 5 minutes at each rap station on significant multipitch rap can cause me an hour messing with the ropes. As you can tell I have been very unhappy with these.
....I climb hard rock and ice, have every dimension and length of rope known to man...but for the Canadian Rockies' hard alpine routes, long approaches with 5.10 and up climbing....this is what I want. Beal Ice Lines are more for ice. Edelweiss Sharp 8.5's still to heavy. Have had several set of these, and they handle the best for doubles when weight means a lot.