OK, so my thoughts on this thing.
-The Pro has a matte top that is a single piece. This means that the hard drive bay is no longer accessible by removing a top piece and instead you just pop off a small plastic piece in the back, unscrew a single screw, and the bay slides out for replacement. The screw on my unit felt like someone had poured superglue into the hole, as it would not budge. Had to spend several minutes using pliers to loosen it, but otherwise nice n' easy.
-Can't comment on system transfers, since I just did a clean setup and re-downloaded stuff overnight, since I wanted to use the same 2TB HDD from my old system and didn't have an extra drive large enough to back it up onto.
-Nice having actual physical power and eject buttons again. They're still too tiny though.
-The console is really not that much bigger than the original PS4, but still larger enough that it might stick out of the shelf in your entertainment center. I've never had this happen with any other console, but this thing just barely juts out from the shelf on mine.
-The "new controller" is the same as the old controller. Yay, translucent part of the touchpad for the lightbar to show through.

What is actually different is that you can now use this controller with the cable as a full USB controller instead of bluetooth, making for less input lag or easy use on a PC.
-Disc game installs are as noisy as ever, but once games are installed, I would say that this system runs quieter than the O.G. model.
-Pro-enhanced games. Tried Titanfall 2 (multiplayer) and saw no noticeable differences that really stuck out compared to the game running on the original PS4. I've seen the screenshot comparisons and it's pretty noticeable side by side, but when playing the game...it looked the same to me. I dunno. Maybe it's just in the campaign mode? Tried Fate/Extella, which is supposed to be Pro compatible, and while I didn't see a visual difference, unless I'm going crazy here...it ran noticeably better. The game generally maintains a smooth 60 FPS on the original PS4, but has some dips. When I was messing with it on the Pro, the framerate was rock solid, even with the screen absolutely filled to the brim with enemies. Nice.
-Are all games supposed to be downsampled when playing on a 1080P screen or is it only the Pro titles?