Rain water bladder tank

Has anyone got any useful information about these rain water bladders I've been seeing a lot of lately? Are they worthwhile or a bunch of ? For those who haven't seen them, it is a rain water tank that is shaped a bit like a matress. It is made of soft "puncture proof" (I'm sure I could puncture it if I tried) material and designed to fit under a decking, under a house, etc. They're usually around 2.7m wide and up to 8m long and 700mm high and they can hold around 8000 -10000ltrs. Best part is the cost, $2100 from B------- warehouse. I'm sure I could source one cheaper than that elsewhere.

Here's an example,
http://www.budgettanks.com/gallery.php
and another
http://www.neco.com.au/product.asp?pID=675&cID=190

Most give you 10 year guarantee. Hard plastic ones are usually 25 years but this does sit under a decking and presumably out of the sun.

Any thoughts or experience are highly welcomed.
Thanks, Dan.

Dan,
I had 2 bladders installed under our new deck about 2 years ago and have had no trouble whatsoever. They are out of the way and the pump supplies the water at new Mains pressure. We bought them from Rain Reviva


http://www.rainreviva.com.au

Our total capacity is 13000 litres and they do all the plumbing. It is a little dearer than hard plastic tanks but they are virtually invisible. You can just see the bladders under the deck during the construction stage. Completely covered now.
Cheers

I wouldnt own one, I just couldnt trust a bladder under the house.
The best Ive seen is the underground poly tanks.

True, but the underground water tanks are so bloody expensive. $4500 for a 6000lt tank. They're great however. I saw a good one which looked like a giant grenade with a port hole on top which is flush with the ground. But pretty pricey but fantastic. You can even bury them under driveways - ie, cars can drive over the top of them.
Wonderplumb, is that the only reason you don't like them? I ask this because ours won't go under our house, it will go under a decking we are going to build outside.
Thanks Skot, yes I saw that site you sent the link to, they've got some good gear.

Dan.

Tricky, just the fact of future sevicing and cleaning, its a nightmare. Not to mention a nice soft bladder that a rat could chew through because he can smell the water through it.
But it comes down to practicality and personal choice in the end.

Installed mine 2 years ago under the deck - given I couldn't get any other form of water tank in there this thing is bloody brilliant. RainReviva supplied everything I needed, however one tip I did get from an installer that gave me a quote was to put down some coreflute before hand - it protects the bladder from anything that's sharp on the ground and also gives it a nice flat platform - even though I installed over a bed of sand the coreflute definitely made it much easier.

Would highly recommend these to people with tight spaces. The RR ones can be daisy chained together too to add capacity.