I received a transparent silicone case with a third party carrying bag I purchased and first wanted to throw it away but gave it a try.

I quite like it as it gives a much better grip and now it’s on my SD 3+ months now. It doesn’t feel bulkier at all(I have normal sized hands).

I used the SD without a protective case for 2 years before and it was also ok.

Unless the case makes the deck hot I think its only a personal preference