Been playing around with these for a few hours in various games.
+ The dpad is great, has a bit of the HORI mush to it but it's larger than the one in the HORI left joycon and has a tighter feel to it.
+ The analog sticks feel very nice, there's little to no deadzone, they move smoothly and consistently, overall remind me of the DualShock 4 stick feel but with a concave top
+ Face buttons feel very good, pressing off center they move with exactly the same force as on center, there's a distinct pressed feel with little mush despite the rubber dome
+ L/R feel good, if you press off center to the left or right it's the same amount of force to depress as Nintendo tends to do with their shoulder buttons
+ Shoulder buttons are nice and big and have the same press feel as the face buttons
+ Stick clicks are a lot more satisfying than the joycon sticks
- ZL/ZR are kind messed up, you need to press right on center, if you're off at all you need to use more force. It's weird that these are screwed up cause every other important button is good, and even the stupid rear "FL/FR" buttons are good.
- FL/FR buttons shouldn't exist. They're right where I want to grip and remind me of the stupid vita rear touchscreen. Thankfully they're not mapped to anything by default but I'd prefer them to not be there at all.
- Ancillary buttons like +/-, Home, Turbo/Assign are rubber and feel like they could rip off pretty easily, plus they aren't satisfying at all to press
- The grip feel on the whole isn't great. I feel like since they're already huge they may as well have just made them larger and easier to handle; probably still more comfortable than normal joycons for extended play but I'd need a few more days to decide on that.
- No rumble
- Pressing "Home" doesn't wake the switch from sleep mode.
As mentioned above, using the left split pad with a normal right joycon isn't as crazy as it seems. You get rumble with this setup, the normally awkward grips are focused on one side and somehow it feels easier to hold, the asymmetric different sticks remind me of the GameCube controller, and you get a better dpad than the HORI left joycon. It looks pretty dumb but feels good and plays well like this.