O.C., I can say what disappoints me about the Lucerne is not necessarily a lack of those little features, but the presence of many of them on older GM G-bodies.
For example, my father's 2000 Bonnie has articulating headrests and my '96 Aurora has three-position lockable articulating headrests. His Pontiac has a HUD, so did the LeSabre and PA (among others), yet no option in the Lucernce for this excellent feature.
His car also has the load-leveling suspension as does the Lucerne, yet has has an air compressor hookup so one can inflate your own tires. I completely fail to understand why this is not a feature on the numerous 2000+ GM cars that also feature rear load-level as its perhaps the best, most useful feature I've seen on any car. To my knowledge, none of the import competition has this.
I also don't understand how the 1998 Seville and 2000 DeVille have express-down windows all around, yet the Lucerne doesn't? Oh, but it has push-down/pull-up switches. Wow. Color me impressed about this meaningless alteration.
To me, things like sunshades and rear headrest are trinkety and don't matter. The molded ones look better, IMO, and allow better visibility. In either case, GM vehicles never really had these features (DHS did have a power sunshade, but how many DHSs have you seen?), so it doesn't bother me. But all these other things that cars on the exact same platform have had for 5 years, 7 years, a decade? That's the saddest of it all.