One benefit is that if you are flushing a brake system with regular fluid in it, the blue will show up in the drain line when the old fluid has been replaced so you don't waste too much fluid. Nice convenience to know when to stop the flush. Its compatible with DOT4 fluids so no worry there.
Several members (gsxr included) use ATE blue, I just stick with ATE gold and flush every 2 years or so.
there is a comparison here but I can't get it to fit my screen for some reason:
http://www.2phast.com/brakefluid.htm