I really hate to see people knocking the stuff too. I think its great as far as I'm concerned.
Out of all the years that I've been water cooling, I've always used water wetter. It smells ? well yes it smells, and if you think it smells bad in the bottle, just wait a few months and change your water for the hell of it. I nearly passed out my first time because of poor ventilation.
Tastes bad ? probably.. The first time I worked with it I recieved chemical burns because "I didn't need no stinkin gloves", I can't imagine what it would be like to swallow the crap.
The only time I have truly experienced sediment/building in the system, has been when reusing parts that probably weren't clean enough. Based on what I've seen over the years, and unless I see some sort of in-depth article proving otherwise, I won't subscribe to the notion that the WW itself is directly responsible for any type of deposits in the system (barring the film thing).
I have relatively clear tubing and I'm just using off the cuff tubing from Ace hardware, and one or two pieces of Clearflex60 The clearflex still appears to be clean and the Ace tubing is a tad stained pink. Thats about as dirty as the tubing is. Except for the tubing attached to my T-line which is opened and closed to add water as needed. That is unprotected, and understandably more vulnerable.
THere is no doubt WW can react with stuff in your system. But it still does its job for just under 8$ a bottle (locally). I think a lot of it has to do with getting the right mixture, and having a relatively "clean" system put together.
I personally don't care much if my tubing gets stained these days, as I am finally preparing to build that box thingy I always wanted to (think "Prometia", but basically housing water cooling euip) so no one is gonna see my tubing anyway.