Me no, I have both, as well as steel
Although personally I find carbon and steel more comfortable than alu, but that is likely as much as the actual bike, its geometry and set up as the material used.
The carbon is my fair weather bike. The steel wears mudguards and a pannier rack, as did the Avail 2 I had (replaced by the steel bike)
Cross brakes are very useful especially in traffic. I don't have them on my carbon bike and I am much more wary about braking in traffic and on hills. On long descents, I have to say that even with the slimmer SRAM hoods, my hands get sore between thumb and forefinger, especially with certain mitts that have a seam there (e.g. Specialized BG gel)
I have them on the steel bike and the Single Speed, and they are very helpful. My two cycling buddies have them and mostly don't use the brifters to brake
@jefmcg (who has a 2012 Avail 2 which has pretty much been ridden to the moon and back
)