How about those new Primochill Rigid compression fittings for their acrylic tubing? Unfortunately, there's really zero reviews out there, and very few impressions. I went in blind; but I know I want to go with acrylic tube, I don't like the looks of the stuff currently out there, and I don't trust the Bitspower stuff.
However, I gotta say, I'm a bit disappointed. For all the hype and excitement, and explicit comments that the tube is "locked" into the fitting - it's really not THAT super secure? The tube "fits" into the fitting pretty well, and is snug. And the fitting itself and the O-ring are nice and tight. Once everything is in the case, it'll probably be fine. But I gotta say, I can easily "yank" the tube out of a very tight fitting. Sure, it take a bit of force - more than I expect the system would ever see - but it's certainly far from "locked" in. I wish I had more experience with other tubing/water cooling to compare - but being my first go-round, I can't really compare it to anything. I do have a push fitting in my garage I ordered a few weeks ago and some E22 pipe - I gotta find it and compare.