Don't know about Astro - never tried it...but tempted.
I've shot 8125, 452x and Dynaflyte97
I found the 8125 & 452x performed very similarly - the 452x seemed to give a slightly "crisper, snapper" feel to the shot.
The Dyna97 resulted in slightly (not by much) lower sight marks, but I found the shot quite nice....plus its considerably cheaper than the other 2. It still performed very well though.
I'd be interested in hearing folks thoughts on the Astro material.