I'm not an expert but have tried epiweb.
this is only my opinion-I have come to the conclusion that :
-Yes it lasts 'for ever'
- Yes It needs to be watered much more frequently than bark or other types of mounts-pots.
Whenever, I ever... .. get my terrariums/orchid 'houses' equipped with a sprinkling system for watering I would definitely use an epiweb like material for mounting.
Interesting subject thanks for bringing this up