My discouraging results are likely due to MOTU driver inefficiencies that are only exposed on Windows 8 (the devices work great on Win 7). I’m left with the conclusion that Win 8 can deliver solid performance, but at the moment the results are very device/driver-specific. (Also, I do not recommend Win 8 yet for anyone who uses a lot of Waves plugins- I couldn’t get mine to work, and neither could Vin of DAWBench.)
The Cakewalk blog’s SONAR results, however, are misleading. There is no evidence that Win 8 improves actual DAW performance, even if other aspects of using your PC seem faster. At best DAW performance will be the same. This may change with service packs and Win 8-certified drivers, but that’s the pulse for now.
But hey, at least it’s not Vista.
EDIT: My recent-model iLok2 seemed to work fine (both after a Win 7-to-Win 8 upgrade, and a clean Win 8 install). One of the plugins I used for the benchmark tests was iLok-dependent. OP, did you have the latest drivers?