Should I just stick with using Dualsense on my deck or get something like the 8bitdo ultimate/king kong controller?
The Dualsense is a really good controller. Would only change it if there was a compelling reason. Plus, if you still have a PS5, using the same type of controller for everything will make switching between systems less awkward for your muscle memory.
For PC, it is not xinput or anything that most games outside of Steam will recognize, but Steam will handle it just fine and if you setup a non-Steam game to launch through Steam then Steam will convert it to xinput for the game to understand.
For deck, it’s fantastic, like a Xbox or Switch controller but with a touchpad. So depending on the game you could have it as a mouse, or three simple buttons(left, right, middle) or my personal favorite as a wheel of options, so you can stack as many as you want there(I find 6 to be the limit of my comfort).
I’ve had mixed luck configuring the mute button(bottom of controller, toggles an orange light), for some games it works great for one more button, for others it doesn’t seem to recognize it, unsure why. This is literally the only downside I’ve seen with it and I use it a ton to play a variety of games