I've seen a lot of posts recommending exchanging money at a Kantor. However, they've all (or almost all) been for travelers from the UK. Is it preferable to bring cash and exchange it for some reason? On all my previous trips to Europe, I've just brought enough local currency to get started and then used my ATM card to withdraw money. This has always been £ or €, though.
Is there some reason I don't want to do this in Poland? It seems substantially easier.