I have the original Apple watch, my wife the original sport. Neither of us have screen protectors. Ours look brand new. I also have a number of 3rd party bands that I like to switch off. For formal events, I switch to my gold band and a gold cover (plastic). For hiking and outdoor activity, I may switch to the black metal band and aluminum black cover that has a clear plastic cover. I don't own an Apple rubber band. Neither my wife nor I like them as we sweat under them. She prefers the melanese band and has two, a rose gold she wears for formal events with a rose gold plastic cover, and a SS melanese band for every day. Normally, I wear a SS band with a gold trim and naked SS watch every day.
As Roland said the saphire is really tough but my wife doesn't have any scratches either. Consequently, these covers, seem to me to be a waste. Maybe if I spent all day as a carpenter, or auto mechanic and wore it it would get scratched up so life style dictates.
My black metal cover with the plastic clear top is awful! Seems that there is always some dirt underneath and it shows up when the watch comes on. I bought a black plastic one that has no clear plastic cover but I have broken a few. FWIW- the cover works fine for the finger swiping and access, even with the bits of dust under it.
You may find something like this a good protective cover for the whole watch if you feel your lifestyle can damage of scratch it- The price of these accessories won't break the bank so you might try one and see if it puts your mind at ease.
Amazon product ASIN B01EFQBQS4
BTW- these aluminum cases are not polished shiny colors but rather dull finish, like a Gold anodized aluminum. If you want shiny gold, only the plastic ones will look shiny and those are not rugged. Also, while I have the original, the watch series 2 has plenty of same accessories too, just do a search on Amazon.