Well, I have more than 30,000 miles on a couple different pairs of BSTs.
My 2005 ST4S has been running BSTs for 6 years and around 25,000 miles. And that bike has not been babied! The rims has dealt with sleet, temps ranging from 30 to 105 degrees. Potholes have been hit. Etc. Etc. I have never had an issue with the rims not performing flawlessly.
By far the biggest problem with the wheels is getting the tires changed. Since my ST4S only used on long trips - usually a week or more and 2,000+ miles - I often need to get the tires changed by unfamiliar shops. This is a concern since a deep scratch can mean the end of the rim, whereas a deep scratch on an aluminum rim is a cosmetic issue. Earlier in this thread a post mentions a rim being destroyed during a tire change. I have no doubt the person changing the tire applied far more pressure than necessary on the rim. However, if it was an aluminum rim there probably would not have been an issue. I've also come across shops that won't change tires on CF rims. OK, I probably wouldn't want them to change my tires anyway!
In fact last year I had new tires mounted by my local shop and they did damage the front rim. Luckily, they are a great shop and they had replaced the rim before I even knew there was an issue! I walked in to pick up the bike and the Service Manager handed me the warranty papers for my new rim. "Uh, what do you mean" I asked. He then explained the rim had moved on the tire changer and been damaged. A local supplier happened to have a replacement in stock. I wouldn't expect that kind of customer service whilst on the road!
BSTs are more susceptible to structural damage than metal rims. There is no two ways about that. However, from my experience they are more than up to the task for everyday riding.
There are horror stories, sure, but just consider how many thousands (tens of thousands?) of BST rims are out there.
Sorry for the long post, but one final note. If I ride the ST4S one day and the next hop on the S1000RR it takes me quite a few miles to get used to how slowly
the RR turns in comparison to the ST4S!