I don't know how you draw your IPC conclusions from the
'pre-announcement' BR data - all we know so far about BR is that it's an excavator with DDR4. Moreover, using single-threaded Cinebench results to draw conclusions of the overall CPU performance of the APU, given CMT, is meaningless - integer performance
might scale N-times linearly with cores will not scale linearly with cores, thanks to turbo-boost, but floating-point performance definitely will not, thanks to CMT.
At the end of the day BR's integer performance might be on-par or slightly better than a 2GHz 8x jaguar, but the fp performance will be decidedly worse. I already sent some rudimentary BR-vs-ps4-vs-xbone calculations to the OP when he asked me about my opinion of BR, so let me repost those here:
ps4: 102.4 GFLOPS (8 cores x 8 flops/clock x 1.6GHz)
xbone: 112 GFLOPS (8 cores x 8 flops/clock x 1.75GHz)
a hypothetical 8x jaguar/puma @ 2GHz: 128GFLOPS
a hypothetical BR @ 2.5GHz: 80 GFLOPS (2 fpus* x 16 flops/clock** x 2.5GHz)
* each "dual-core" module has one fpu.
** assuming Excavator keeps Steamroller's dual 128-bit FMACs.