Really? Interesting... whenever I am in Poland I stand in awe and bewilderment before a (seemingly) never ending successions of consonants (mainly c,s,z,r,l,w and k) -- and I am never able to tell how a word is pronounced. Its probably a bit like in german, where a group of consonants can form exactly one phoneme ('sch' -- [∫]).

Yes, digraphs involving z are quite common in Polish so it's not as bad as it looks. Still, English would never have a string of them like "szcz" ("shch" in English orthography).