I can now hear the purists screaming for blood.
Athena, Tiagra and Apex in the same category?
And frankly, they have a point. But this is a comparative that is arranged so that whatever is first billing in these three component companies will be compared with the #1 of the other company.
Here, the road just forks into completely different directions. Let’s just start with that fact that Campy still has 11 speeds running, while Sram has gotten into 10 and Shimano is on nine (but with a whole hell of a lot of gear ratio options). There are still components with carbon fiber parts with Campy (the crankset and the shifter levers). Shimano has a three-chainring crank, apart from its regular two-ring affair. Sram has a black or a white version of this group.
It is staggering to see how much of a difference there is and how fast you see it as you go down the hierarchy. Campagnolo has definitely shown itself to be the most elite of the three, with all its high-end materials and technology, even if it is in the fourth category down the list. Shimano has variety and the reliability stays but the fancy names have all dropped off by now (even though there is an integrated crankarm/bottom bracket; not Hollowtech II, however). Sram is considerably less showy than its high-end line but the Apex still maintains the design lineage.
It all boils down to two things: how you ride and how much coin you have to spend. And oh, having fun, of course.