We’ve been slowly moving to Index controllers over the past year, so far the only issue has been them getting damaged, but still not close to what we experienced with Vive wands, and thankfully valve has replace any controllers we have had break so far.
The small system button was initially a concern, but with a good explanation, and having the customers turn controllers on themselves so learn it’s position it hasn’t been an issue. I anything in my experience it has meant less accidental presses from confused younger players.