Around 2007/2008, Gibson began hailing the then current TB Plus pups as "new design" in their advertising descriptions and model specifications. For once, that might have not been just marketing blurb, but the truth. Certainly, the new pups have even more ooomph, at the cost of some clarity though. Still a typical TB Plus sound.
When I listen to the TB Plus pups of my 87 Gibson IVs/Vs (which have a tendency to become microphonic), they sound almost singlecoilish in nature in comparison to the freqeuncy and volume brunt you get today.
Doesn't your Blackbird sound much leaner than your 2007 IV? Mine certainly does.