I paired the 40 s3 with the B&W because only the studio 20 s1 was around
source and integrated amp was denon.
I am so glad I don't have a golden ear ... (again, it was the wife who noticed a big difference but mentioned "nevermind for that price" - she did not know which of the two speakers were running)
sure there was a difference between the two, but if I would assign ratings to the difference it would be paradigm 98% b&w 97-96%. the difference was in the soundstage, the vocals were "higher" or simply "louder" than the b&w.
you have to consider though that the B&W has one 7" driver doing all the work, while the studio 40 has two 7" drivers (one for the mids, one for the lows).
I'm thinking the cheaper floorstanding 603 b&w with separate mid and low drivers will be enough to match the studio 40. (or the 604 will be enough to beat it)