I have been eyeing the Sire U5 as well. I talked to Pitbull Audio about it (chat) and they told me about a week or 10 days ago that (after he checked) they were supposed to be shipped to them on a slow boat from... wherever in 2 weeks; and then after 3 weeks in transit they would arrive at Pitbull's warehouse, so about 5 weeks in all before truly "in stock" which would be 3-4 weeks from now. Just FYI for anyone considering ordering one. I prolly shouldn't say but I was offered 10% off to pre-order, after I asked if their 20% off coupon applied to Sire (I knew it didn't). $450 for one aint bad at all, once they are in stock I doubt they'd offer the 10% off then (my guess anyway).
As regards bridge pickup placement- it reminds me quite a bit of my Squier Jaguar (32" scale) which is passive with a P neck and J bridge configuration also. Same controls- Vol, vol, tone. The P pickup is stronger than than the bridge pickup so most of the sound comes from there; it's well-placed- in the "sweet spot". The bridge winds up being a tone blending option to add in mid/clarity/cut; it flavors the output of the P, more than being an equal partner, I guess you could say. I do like the tone nonetheless and the jazz PU is useful - just less powerful. So, just guesswork, but based on placement on my Jag experience, that's what I'd expect. And that doesn't dissuade me at all.
Still, I like the Jag's Who knows, though, until one of us has one in our hands, amirite?