Comment by submeta

I tried both. BetterTouchTool does support the no-animation left/right space actions, but on my machine InstantSpaceSwitcher felt a bit snappier for actually moving between spaces, so I kept that for my keyboard shortcuts for previous/next space and direct jumps to a specific desktop. I still use BTT for Mission Control / spaces preview. So for me the final setup is: InstantSpaceSwitcher for fast space switching, BTT only where it still adds something.