I'm Polish, I can understand 80% when Ukrainians speak without ever learning it (and about 50% of Russian).

But only few years ago I've learnt cyrylic script (by accident, when I was in L'viv for a week ;) ). It's not hard, but it takes time, and I still have to say each letter in my mind when I read cyrylic, it's awkward and takes a long time compared to Latin-based foreign languages.