Hi,
I definately qualify for Wop wop status!! I have a 22,000L plastic water tank for the house which collects rain water off my roof. It comes out of the tap as soft and acidic as I can measure. Great for my SA corys, tetras etc. I modify the water using a rift lake recipe (MgSo4, bicarb & salt) for my frontosas/altos etc.
Although this is a challenge I seem to be able to maintain good water quality, test it all regularly to make sure all is ok. I guess it depends how much effort you want to put into making sure the water is right for your fish. If you just want to turn on the tap and change your water without thinking about what you are doing you may have more problems than if you were on mains supply with a more neutral ph etc.
At least my water has no chlorine in it!
Joanne