I prefer to read without a cover and have always used a protective, padded sleeve to store my ereaders when I'm not reading. I will use the Oasis cover in the same manner — pop out Oasis for reading, pop it back into cover for storage and charging.
I'm hoping Amazon will eventually offer covers as an accessory you can buy separately. I got the black cover because I was too impatient to wait for the merlot

but if the merlot were available as an extra accessory, I'd probably buy it, then swap back and forth depending on my mood