I picked up an APX Target to complement my existing APX and I'm sort of glad that I did. It has a couple of extra features that were hard to confirm remotely on the Internet, so I'm glad that I have one now and that I can confirm that in addition to the listed features (RDO, Fiber Optic/blacked out rear sights, no-grooves frame, longer barrel/slide, 4 mags in the box, green striker), it has a distinctly enlarged magazine release and slide stop/release, and has had significant work done on the internal design to improve lockup and barrel/recoil spring/slide fitment. They've made clear changes to the front of the slide, the recoil spring design, and the barrel design.
I'm hoping to get out to do some accuracy testing with it, which will prove to be interesting.
And since I'm going to be doing some testing with shot timers at my next range trip with my new shot timer (indoor range friendly! Thanks P-F), I should also get to see if there is any significant difference in behavior on the timer between a no-groove and finger-grooved frame, since I can swap the frames on the guns around. While it's mostly irrelevant, it will be a fun experiment.