The bottom line is an air shock (or any shock) is only as good as the loads placed on it and they don’t perform well with wildly varying leverage rates. That’s why you see guys like PUSH doing more custom damped shock tunes for SC and Intense VPP’s than any other design.
The E29 is far from perfect. Sure I like 29″ and I own an E29 but I’d still change things about it. The suspension however is hard to fault.
Two things re Gwinn/Brosnan. Gwinn had spent two (three?) seasons on a Trek with a 450mm rear centre. Troy doesn’t know any better, he’s been riding the bikes for years and he rides a small so the rear centre is better balanced with the front.
Also, IMO, Brosnan is an unbelievable talent.