Only been to Poland once (and that was a good 15 years ago) but I thought It was great, sure some parts of krakow looked kinda f'd up (not thats a bad thing, to me it just adds to the charm) but overall I loved it. The people I met were very nice and I was never under the impression that "...the people are unhappy, never smile, never speak to you or want to help if you're lost.." it was rather the opposite.
But I was just a kid back then, maybe they treat adults differently.