Good discussion and lots of helpful advice.
I am finding that on close inspection, with light falling just the right way, I can still see "pigtails" or curly-q's from the DA. Hand sanding would likely be better in this regard, as I'm finding these difficult to buff out. Maybe it's my cheap sandpaper, maybe it's my technique, maybe it is expected when color sanding with a DA. However, it took me hours with the sander to get the paint flat. I can't imagine how long it would take by hand.
I ordered some 3M Trizact 3000 grit sanding discs and I'll wet sand using that to see if that does better on the pigtails. I may try to polish with the "Meguiars twins", ie. M105 followed by M205. Some say my 3M perfect it system is for use on a rotary polisher, while I used a DA polisher. I'll let you know how that goes.
Also, when I remounted the doors I am having trouble getting proper fit. I am thinking the patch panels I put on the A pillar area in front of the doors changed the size/shape of this area slightly. I may be thankful for the ability to blend the single stage paint!