"It's what the pros use" does not cut it for me.

I don't assume pros always know what is best in regards to adopting new trends. This is especially true of road racing that is heavily steeped in tradition and highly followed norms.

For example, only recently are we seeing tires larger than 23mm in the TdF. For years people have been pointing to the benefits of larger tires, but the pros were very slow to change. I am sure that on these internet boards, people were pointing to the fact that the pros used 23s as proof that they were faster than 25s. They must be, the pros use them. As it turns out, the pros were wrong.

I am much more familiar with the mtb world, and watching xc racing was similar. Many non-pro riders had ditched the narrow bars, long stems, and bar ends in favor of wider bars and shorter stems YEARS before many of the xc pros did. Same is true for the adoption of full suspension.

So, the fact that pros are not flocking to disc just a few years after their introduction to road bikes does not mean a whole lot to me. Give it ten years, then we'll know.