They claim the plastic is food grade, so that's covered.

The thing I like about this bladder idea is that I could build a raised and covered platform to place it in, and then store things on top of that platform.

And if I move house, it's much easier to deal with than 55 gallon drums.

I really like the idea of a nice 200 or 250 gallon food grade tank, but I'd find it difficult to get something like that delivered and into my house without the neighbors noticing. Think I also like the idea of having my water storage spread across several containers so that a single failure of some kind doesn't eliminate my entire water supply.

I guess I really like the potential flexibility and easy transportability of the aquatank, but in reality, that flexibility and transportability will be seldom used. I guess that makes my decision for me.