I bought a pair of these shells for a set of Joy-Cons that had fitment issues, including some nice sharp edges, straight out of their brand new Nintendo packaging. Installation was about as simple as you can hope for with the Joy-Con's spitefully tiny internal parts (mind those trigger springs!), and once finished the shells fit together more nicely than the originals. I opted for clear/transparent shells and they look awesome.
One note of warning: the mounting post for the **** that holds the charging rail to the rear half of the shell is very short and uses a relatively coarsely threaded ****. Even though I was being extremely cautious, I very easily overtightened the **** and stripped the inside of the mounting post. Doesn't seem like an actual problem now that everything is back together—it's not the only part holding the charging rail in place—just something to be mindful of.
As for the mod, the D-pad feels so much nicer than the standard four separate directional buttons. Reminds me a bit of the clicky D-pad from the GBA SP, which I personally liked a lot.
Nintendo Switch D-Pad Version Joy-Con Shells - Standard Colors
Love the look of the clear green, almost identical to the clear dark green N64 consoles. Fitment is pretty much perfect and the d-pad upgrade is awesome, makes the swap worth it for that alone for me. Swapping everything wasn’t too tricky, the joy cons aren’t the easiest or trickiest controllers to work on though everything is pretty small and it can be easy to lose the trigger springs if you don’t remove them before going after the trigger itself. The tiny screws will strip and/or cross thread very easily!