At first glance I think cards are cleaner, though I’d have to try a live cardless instance to really form a strong opinion.

Would this be an option or replace the current look?

I’d probably need to see it in action more before I could make a judgment, but I think it could be nice.

Update:

After looking at the preview, I think I prefer the current card based design.

The cardless one is nice in that it is more space efficient (less whitespace), but the cards are easier to read and provide a nice contrast. I think the cardless design is almost too flat, while the current card one b/c of the different background, makes it a bit easier to content.