It looks and reads disgusting

see, I'm not a fan of it, but now we'll have to throw hands

It's delicious

It does not taste like wet bread if that's what you are afraid of. Also not like nonalcoholic beer. It's kind of hard to describe it, but it is a normal / not too weird tasting drink. Quality and taste varies quite a bit between different brands.

There are also many that are not true kvass, but drinks with kvass flavouring so that's another thing to keep in mind.