Here is an interesting video that got posted to youtube a week ago. It shows a CF shelter (in this instance, a ZPacks Hexamid, made from 0.51 cuben fiber) getting nailed from some rather large size hail.
Bounce forward to around the 4 minute mark to really see it.
I am not implying that SilNylon or SpinnUL or anything else could not handle this - rather the fact that any shelter can take this kind of a beating from hail of this size is pretty sweet!!
From my experience, the quality of manufacturing plays a large part in how well the durability of a shelter is going to be -- and specifically I am talking about the bonding (taping) aspect over the thread lines.
Companies such as MLD have set the bar for how to properly build a CF shelter. Companies such as HMG sort of go above-and-beyond (overbuilding) their CF shelters IMO. Companies such as ZPacks and SMD and LHG (and others) that have started to bond their seams are moving forward with the shelter durability issue.
Without a doubt I would put a HMG Echo (I owned a Echo I and an Echo II) up against any shelter in the UL hiking world when it comes to abuse it could take. Other shelters such as my 0.34 tarp and other 0.34 tarps that have been made by guys such as Steve from Suluk46, well they obviously have some serious weaknesses - but we are the few amongst the already few and are not out there being stupid using them in conditions such as what the video above shows, they are strictly summer-time shelters, I think I pushed mine into shoulder season once and worrying about it was all I thought about the entire hike, so I have never done it again. I would put the 0.74 CF tarps that MLD make up against any equivalent SilNylon tarp that is out there as well. Likewise, since ZPacks has made the move to seam-bonding they have made leaps and bounce in durability - initially they did not thread bond to save weight.
Anyway, yes, there is more than enough hikers around the world using CF to more than prove that CF is a viable shelter/backpack material. More than one business exists today that make nothing but CF gear - and these are businesses that employee a fair number of employees. They would not continue to exist if hikers had discovered CF was a failure.