I've got the old version of the R300, used it for everything from dogging single pitch sport (a lot) to dolomites multi-pitch trad and even alpine stuff. It's the best harness I've ever worn, very comfortable and versatile. The fancy weave stuff makes such a difference compared to other harnesses I've owned.
I've found the 4 gear loops to be plenty, you can fit loads on them, and I know you were asking about the BD but I've never had an issue with the fixed leg loops, even over multiple layers.
Durability is fine as well. 4 years old, it gets used all the time and it's in great nick.
The only slight irritation is that sometimes the gear on the front loops can end up sat on my legs, (usually happens when it's the last thing I need,) but this is mainly (I think) because it's a little too big and the gear loops sit too far forward as a result.
Can't recommend it highly enough though, I'm not going to bother looking at any other makers when it's time to replace it.
