I think it would be great stuff for hooking up a Bag-n-box soda outfit...
If I'm not mistaken...your ordinary tubing used to connect ice maker kits is polyethlene...and I've never noticed a taste associated with it...so I think the material would be first rate.
Having said that...the drawback is the size of the tubing. In order to "balance" a draft system...you have to have enough resistance in the line to enable you to have your CO2 regulator set at a pressure that will maintain the desired carbonation level in your beer...but by the time it reaches the tap...be low enough that it doesn't cause excessive foaming in the glass. Most recommendations are to use 3/16 id tubing for this reason. A length of 5-10 ft of 3/16" id line is preferable. I use the 1/4 id line on my Stout rig...but it's being fed to a restrictor faucet. My regular faucets all have 10ft of 3/16" vinyl tubing and I have no foaming issues.
There are techniques for using epoxy mixing inserts in the line...which would help you balance the larger ID tubing...so you CAN make it work.
The line you're talking about may be difficult to use...because it's not as flexible to coil up a length of it in your fridge...because it's stiffer than vinyl tubing.
The other drawback is that it's not as easy to tell if the tubing is clean...when you go to flush out the beerstone that builds up from time to time. Vinyl tubing is clear and easy to inspect.
I think it would be better used on the GAS side of the setup...personally.