Hmm....I thought of just using live sphagnum moss as hardening media at first but some species are doing so well that I'll be leaving them as they are. However, I'll be pulling out one plant each to be potted in peat/sand mix for comparison.
My experience so far...
D. falconeri (a few plants rotted and the remaining plant grew very slowly; but then again the species is the most sensitive of the lot...it has been moved to peat/sand mix)
D. broomensis/D. lanata/D. darwinensis (prefers lower water level, will react when LSM is flooded even for 1-2 days i.e. water at the crown but recovers and continues to grow well if water level is lower)
D. ordensis/D. kenneallyi/D. paradoxa/D. dilatato-petiolaris (ok with fluctuations in water level; best growing of the lot)