I’ve heard Poles describe Czech as sounding like a baby speaking Polish. ;)
Yup, that’s what my in-laws and friends say too. I can’t hear it myself, but I’m not a native speaker.
To me, Czech is softer, but only slightly so, so I guess that’s where it comes from.
One thing I learnt early is that szukać (to search) in Polish sounds like “šukat” in Czeski which means intercourse. And “to search” in czeski is hladanie