My bike came with 105 5600 levers and BB7s, from back when there was only a road version of the caliper. I have four years and 12,000 miles on them, still using the original front cable even. No problems, but as JeffS noted, they require a longer lever pull than Shimano rim caliper brakes. There is a workaround.

I specified the lever model for a reason. I'm in the middle of replacing the 5600 levers (original 10-speed 105) with 5700 (new, under-the-bar-tape 105) to get the shift cables out of the way of my headlights. There is mention in the instruction sheet that brake cable pull is different in the 5700/6700/7900 series levers. The instructions for the Ultegra 6700 rim calipers say the same. I didn't finish the job last weekend and only have time to work on the bike on the weekends, so I can't say yet if this is true or what effect (if any) there is with the BB7s.

The instructions also say you can't shift, you'll go blind and your children will become sterile if you don't use the new super ultra special 5700/6700/7900 chains. The bike I just built using Ultegra 6700 shifts just fine with the same KMC X10.93 chain I've been using for years. You can never tell how much of this stuff is true or how much is just marketing BS. Although my vision is blurry...