If the need is for greater initial bite, linear grip, exponential grip, improved performance in wet conditions, dry conditions, longevity, less noise, cool operation, there are pad materials for each of those, and there are pad materials that do it all with compromises. The learning curve is very short for using discs, just like using new rim brake pad compounds, but nothing about their operation will bite you the first time out. The bed-in period is the time to become accustomed to a particular caliper/pad/rotor performance characteristic, and until the pads & rotors are bed, performance will be far less than optimum.

I have disc brakes on my road bike, the front fork is a skinny straight blade, it doesn't twist under brake, whether hauling down from 40+ mph or riding the brake on a 30% bumpy descent. It may be detectable in the lab, but it's not observable by me.

I can lock the rear wheel on my vintage bike, rear wheel lock up is more about the fingers and not so much about the brakes. For the fronts, lock up threshold is more brake pad/tire compound dependent. I did configure the rear disc to be less grippy, so as to reduce the fingers' influence.

Rotor size has its place when braking repeatedly or continuously under high load. Road "racing" demands light brake usage, the discs on a racer could be quite small and still be affective, so rotor weight would be less of an issue.

Disc brakes are not superior in all situations, just as rim brakes have their less than best moments. I feel love for my disc brakes when they remain fade free on that bumpy as all get out, ride the brake, major steep descent. My rim brakes go soft near the bottom of that hill, and there are usually shards of rim surface embedded in the pad afterward. It will take some time before bicycle disc technology advances to the road race level, but it will happen.

A couple additional points, my rear disc hub is 130mm road spacing, and as I mentioned earlier, disc brake noise can be eliminated or reduced drastically with pad choice.