I got my Echelon a few weeks ago during the Gear-Up promo. I don't have any XD save for my XDE and XDM-40. The latter can be ignored as we're talking compacts here, not duty-sized. My XDE is pretty darn slim, considering it's a single stack. I like the fiber optic front sight, it helps me focus on what matters. But the Echelon has that and more - the front sight also has tritium. All of that co-witnesses with the RDS, which I found needed to be adjusted after shooting my first mag.
If after a while I don't care for the red dot, I can still put the cover plate on. However, I'm willing to give the optics a try. I was raised on iron sights and that's all I've ever used on a pistol till now. Only time will tell. But I absolutely do NOT regret getting the Echelon... Chassis pistols are the future!