Teufelberger lists elongation for their ropes as a percentage between 50 and 150 kgs. I weigh about 80 kgs and a real hard push on my digital scale appears to approach 150kgs. I guess that's what they are getting at.
Xstatic = 1.4
Km3 max 11 mm = 1
Km3 max 13mm = 2.1 (why higher than 11mm?)
Km3 13mm = 1.9
I have read some people say they think km3 max 11mm is bouncy. My experience is that it was not. I have never heard anything about xstatic being bouncy. I have not used xstatic or km3 13mm yet, but I will see about the km3 13mm soon. I rarely have the pleasure of a tip higher than 70 feet, usually less, occasionally a little more. On a rare occation I get a 100 footer. Sometimes on a base tie which does induce much more bounce. I think people who climb taller trees will certainly feel more bounce. Different climbing styles will make a difference. Even when I get to climb tall trees durring oak trim season I rarely ascend all the way to the top before I start working. So if the rope is a little bouncy for 15 or 20 seconds while I get to working height, it doesn't really make a difference in the long run. I also just got a knee ascender. Previously I was on a foot ascender and a foot loop on a hand ascender which didn't make for a real smooth ascent anyway, but I got pretty quick on that setup. I could easily do 50 feet in about 20 seconds without breaking a sweat or trying to be fast. Long strides. Still, I could feel a difference when I went to scandere from km3 max, it just didn't bother me. Increased ability to grip the rope was more important. I often pull myself up short distances by hand. I had to use a hand ascender on km3 max 11mm far too often for my liking. Rope weight is nothing to me. 99% of the time I am on the rope, the rope is not on me, why would an extra pound or two per hundred feet matter? I climbed ddrt on blue core for 16 years before I went srt. Its all butter in comparison, I'm just fine tuning my butter. But those 10 to 20 foot hand pulls on 11mm really suck in srt. Thats been the only down side. Oh, did I mention imori? Bdb don't like it, hh2 actually flattens it to where I am grabbing a flat ass rope wondering if my hitch is going to keep holding it. It does give good grip. Further more, I can't see my 174 pounds(without gear) causing much stretch in a rope with 12,000 lb tensile strength (km3 13mm) but who knows. I'll try to get some quantitative comparison on something tall enough to matter. I currently have 200 ft of scandere, 150ft of blue moon, and the 150 feet of km3 13mm coming in the mail. For that matter, I have a nearly unused 150 feet of blue core I bought for one of my guys available too. It would be fun to get them all canopy tied at 100 feet on something that doesn't flex and see I can make them bounce.