I've been using Campy Super Record (last generation) since 2010 and have transferred it to multiple framesets over the life of the group. While it performed great over the life of the group, over the past year or two, it's performance wasn't what it use to be. Enter Etap. Why did I wait so long to switch to a electronic groupset? It is without a doubt the easiest groupset I've ever installed (which included mechanical Campy Super Record, Campy Record and Dura-Ace). No installation was ever this easy. And no shifting for me has ever been this precise. I use to say, I don't need electronic shifting, mechanical is just fine. And mechanical is fine, but electronic is so much better.
Before purchasing, I read all the reviews on electronic groupsets from the big three, and they've all received great reviews for shifting, but none had the ease of installation like Etap. So all groupsets being equal in shifting performance, wireless beat out the other options for me. Since I've been building my own bikes (road, MTB, BMX, fixed) for over 20 years, not having to mess with internal wiring is a major factor.
The shifting is intuitive and easy - I had it down during the installation before I got on the bike for it's maiden voyage.
A word on compatibility. I'm using a Campy Record cassette and there are no compatibility issues - flawless shifting.