Paul,
I'm interested to know what you think about your bull horn bar on long audax rides.
How does it compare to drop bars, regarding long term comfort?
I'm a convert to Bull-horns.
I didn't necessarily want them or ask for them, I just got them when I purchased this bike and I love them. I've only done a max of 100 miles on them (during that ride in fact) but I've never once thought about comfort....that's about the best thing I can say about them. (They are very, very, padded...my guess is triple-wrapped, maybe just double).
They aren't very aero as they are rather wide but that gives lots of leverage for Single-speed climbing.
I don't know what bars they are (ask Revrob) or whether they would suit you but I like them a lot.
Remember, I have 7 bikes, since I bought this bike in November 2012 I haven't ridden any of my other bikes.