Saw this while watching drag racing on ESPN:

http://www.pipemastertools.com/

I've used a free program called tubemiter.exe, if you put it in your favorite search engine you'll get plenty of hits. It's a very small program. You enter the OD of the tubing, the wall thickness, the OD of the tube you are mating to, and last but not least, the included angle of the joint. It will calculate the shape, and you can print it out, warp the tube, and cut as needed.

I know it's not super fast, but you can make crazy tight joints with it. The guy who designed it was into building bikes that are brazed together, requiring a near perfect gap. For automotive mig or tig welded joints, you can get the end cut to shape in a couple minutes without too much trouble. Tech weenies will say an air tight joint is good for welding because the back of the joint is less apt to get contaminated by atmosphere.

That being said, I like the tool you found, very good for odd shapes

These guys make there version of those too, have alot other neat stuff
i have there tubing bend protractor.
http://www.mittlerbros.com/