The Trijicon HDs have long been my go to for handgun sights, having nearly a dozen sets, on various makes and models. I've used the XR version as well, and prefer the Standard HD's because of the larger amount of photo luminescent paint present on the HD's .144 front blade over the HD XR's Thinner .122 front blade.
Recently I picked up a couple sets and noticed some changes as well as QC issues. The finish has changed, to a deeper black versus what my older sights appear to have almost like a black oxide finish. and the screen on lettering that almost always wipes off, has been changed to laser marking which is great! The newer HDs also use a longer front sight which is disappointing and to me a down grade over the original HD front sights.
The issue I have ran into with my HD sights I picked up recently is that the quality control is iffy on the rear sight, in that there is an excessive amount of adhesive left over from installing the tritium vials in the serrated rear sight. I dropped Trijicon an email, with photos regarding the QC and adhesive issues on the new production rear sights, and was told to contact a phone number at Trijicon HQ, which has me worried its the "new normal" and they're all like that.
I'm currently looking into getting a set of the new Glock GMS Night Sights that use a near identical Front and Rear width to the Trijicon HD series that I've enjoyed using so much.