Better than a non horseshoe I mean. I don't hear Chris Squire sounding fundamentally different to other Ric, just more extreme. And I can-t imagine that picking up the signal of the strings from above leads to a vastly different result to picking them up from below though I'ne heard that the Ric' cavernous bridge pup routing contributes to the sound and that its effect should be less with the horseshoe.
I don't care about the looks (nice, but no must-have), but I'd buy one if it would make one of my Rics sound very much better or at least different.