Was lucky enough to stop by trijicon at the NRA expo in dallas this year. Played with all colors, variations, etc.
I have the HD on my G19 and the HD XR’s on G17 and G26. My wife wants to steal the HD XR’s off mine and put on her 17 and 26! They are the chartreuse color, picks up sweet for me indoor and outdoor. She prefers the orange.
Now, as far as the difference goes on the sights... if you’re truly focusing on the front sight like you should... you won’t notice a difference. But that is labor and work to do correctly. Transitioning targets, be it plates, targets, gssf, etc. the HD XR’s will win. That little bit of space will allow you to stay focused on your front sights during transition which is sweeter, faster, and sexier. I noticed a huge help on plate racks at gssf using them but that may just be me. Either sight is really nice. Please note that my wife and I both agree that we like the rear sight on these as well. Why? The rear sight does have tritium in it, but the dots are really small and do not distract you from your front sight. That seems to be huge for accuracy and focus. All in all, we approve!!!
Hope this helps, left me know if I can clarify anything further for you.
All the Best!