Lets face it, the entire thread is hearsay and speculation. Hence the title
IMHO the engines will be evenly matched, although one or two may have some advantage in the right circumstances. Also with the technology being new, we'll see teams leap frogging each other as they get to grips with how things work. Then they'll reach a steady state in mid to late 2015 when the pecking order is established with little variation.
Hopefully that covers all bases!