It is a huge job to change it all but I think it's worth it.
I don't like too many different backgrounds as I think it looks a bit messy. There's no way to switch items around on Etsy, so if you use different backgrounds, they are always mixed up.
I have done it for some of my greetingcards already.
You can see the difference here:


Now I just need enough bright days to do more photograpy...