My Wesley Special (pulling 41#} came with a BCY-X String on it and an extra Astro Flight string. I just got around to trying out the Astro Flight.
It isn't as quiet as the BCY-X (don't use any silencers on it) though I haven't experimented with brace height at all with the Astro Flight.
The Astro Flight is faster. I have to adjust gaps by about 5 yards. Very noticeable at 25-30.
It's a much thinner string. Any downsides if I can get it as quiet with brace adjustment? It's still very quiet...just not as quiet as the BCY-X
