pvaudio - glad you mentioned that about Cyberflash. I thought my memory was going. I keep reading comments about how stiff Cyberflash is, but I was remembering it as a softer string.
As far as Luxilon ALU, I've not found anything like it. It has that Luxilon drop where a ball which seems like it is going out dives in at the last second. It is a stiff string, yet feels springy in a metallic-spring sort of way. If you swing hard, you can feel the string give and shoot the ball out with spin, but the actual deflection is very small, so it maintains control.
For me, there is no question that I play the best with full ALU (I like the Rough or Spin best). I hybrid it with AlphaGut2000 usually because that is easier on my arm, and there is only a tiny bit of difference between that and a full Lux job.
Because of the short time the stringjob is at its peak and also because of comfort, I'm playing with gut/poly right now during the winter. (I actually play well with dead ALU, also).
If I play tournaments during the summer I will play with ALU.