So I tried out the HORI D-Pad Joy-Con with a range of games: Labyrinth of Refrain (menu and dungeon navigation is done entirely with the D-Pad), Gunbird 2, Namco Museum, Money Idol Exchanger…
The D-Pad is decent, if a bit stiff to operate. It’s a ‘mushy’ D-Pad with presumably rubber switches so there’s no clicky feedback to each press. I had no trouble playing games competently with it.
For what it’s worth, I did notice, under the inputs test page in Settings, that quickly moving left-right-left-right on the pad will register the occasional up or down press, so it’s not as precise as a clicky pad or the Joy-Con buttons. But it is a lot more comfortable if you’re continuously moving directions, thus also making it more versatile to different ways of using it.
The rest of the design is so-so, though, and it makes you appreciate the switches Nintendo uses for the buttons. Presumably to cut costs, the minus and capture buttons are rubber buttons with mushy, poorly defined switches beneath them. They are difficult to press and as a result, introduce the feeling of lag when you use them. L and ZL aren’t rubber and have switches, and feel better, though different to the R and ZR of the accompanying, official Joy-Con. The stick must be a Nintendo part as it’s identical to the official Joy-Con.
If you’re going to be playing a lot of shmups and fighting games in handheld mode, I think it’s worth picking up.