Could you report which prefers which and how hard/soft your water is? I'm planning a large crypt-heavy tank and looking to try some new things, but I want to work with my water, not against it.
I should probably define here, when I say hard or soft water, I'm (incorrectly) referring exclusively to carbonate hardness/alkalinity/KH - I still maintain a decent level of GH for the accompanying maintenance crew.
Mine would be a pretty small sample size so by no means definitive and it goes without saying there are a number of other factors that might be affecting the growth rather than specifically the carbonate hardness. This is just my limited experience:
Nurii (and variants such a pink line) - grow like weeds in harder water throwing out runners everywhere (to the point of being a problem), but grow very slowly in soft water
Bullosa - also grows very well in harder water and produces runners, but grows very slowly in soft water (though still relatively slow)
X Purpurea - also grows very well in harder water and produces runners, but grows very slowly in soft water (though still relatively slow)
Albida Brown - really struggled and grew slowly in hard water, grows much quicker and larger in soft water
Crispatula - currently growing well in soft water, but took 4 months to start, haven't tried in hard water
Cryptocoryne usteriana - ain't growing for me in soft water so far - though significant lack of light could also be the cause (never tried in hard water)
Spiralis Red/Spiralis Green/Spiralis Tiger - all seems to grow in both hard and soft water, but definitely thrives in soft water
Lutea Hobbit - grew very slowly in hard water, but kept its typical 'hobbit' form. Very strangely in soft water grew much faster and converted to a form with very large red leaves - presumably reverting to its original Lutea form (?)
Aura - very slow growing regardless, but simply won't grow in hard water and dies away, in soft water it is growing (so far) albiet very slowly.
Wendtii Green/'Tropica' - grows like a weed in hard water, grows okay but more slowly in soft water
Silver Queen - static growth or faded away to almost nothing in hard water, very slow but better growth in soft water
Striolata/Keei/Eunoii - all three degraded away to nothing in hard water (never got to try them in soft water)
Miss Lingga - (my favourite crypt) seems to grow equally slowly in hard and soft water
Beckettii 'petchii' - also one of my favourite crypts, seems to grow well in all types of water
Parva - really variable, grows or fails in both with no apparent rhyme or reason!