We're planning to take a bus from Cracow to Zakopane (Poland) in June, with our 7-month old kid.
I've never been to Poland, but last year traveled several times by bus from the Baikal lake to Irkutsk (Russia) and would never like to do that kind of trip with a baby (drivers consistently went too fast for my taste).

How is the ride, traffic, and general speed? Would we find a baby seat or would we need to bring our own? I'm asking because we could alternatively take a (slightly slower) train.