What are you missing without it? If you don't missing anything, I wouldn't bother. The Nitro Deck seems to add back buttons for example, but they'll probably be limited to simple button mappings, nothing fancy like you could do with Steam Input for example.

I have one. I like it, I find it much more comfortable than joycons in handheld mode, and the buttons are more like a pro controller (compared with joycons and grips like the Satisfye). It feels more stable than the Hori Split Pad since it goes beneath and behind the screen, but it does add a bit more bulk. My only complaints are that the LED is on by default (you can turn it off but will turn back on after waking from sleep), and the release button can be a bit hard to slide.

My wife got me one for Christmas. I like it. My hands are big so the standard joycons feel too small. My only issue is the d-pad isn’t in the best spot. But all in all it’s a comfy grip.