I tried these two speaker packages side by side a couple of years ago, both driven by a Pioneer receiver (can't remember which model it was, but it was around the £700 price bracket). After auditioning a couple of blurays and CDs, I much preferred the Focal satellites. The B&W PV1 sub is better than the Focal offering though. This is born out when you look at the satellite-sub price ratio for these two packages: £1000 satellites vs £500 sub for Focal, £550 satellites vs £1000 sub for B&W (roughly speaking). The retailer suggested that I could always go for the Focal satellites and the PV1 sub, at an extra cost of course.
In the end I went for the Focal package and have been very pleased with it. Originally I had an Onkyo 607 receiver (it was about all I could get hold of at the time of my purchase as many receivers were out of stock), but I’ve recently upgraded to a Pioneer VSX-LX53 and it has made a world of difference. The Onkyo certainly had the oomph factor, but the Pioneer serves up a greater level of detail and control, and it can currently be picked up for a great price + a free bluray player thrown in.
Ultimately though, you need to compare side by side for yourself.