Anyway you look at it it's a disaster. The only strong point should have been the overclockability but... On air all reviewers barely reached stable 4.8 with a power consumption that needs to be sustained by a nucular plant.
Haven't seen a comparison yet between say 2500K at 4.5 (easily attainable) and 8150 at 4.8. I'm pretty sure the 2500 is better in 90% of the benches with half the power draw and 20% less expensive. I think the worse part of this launch is that AMD is compromising its position as bang/buck CPU provider. The whole lineup of FX pricewise is a mess.
I can't even think about the performance compared to the competition - and I would include here also the Thubans and such - of lower level Zambezis, the 6000 and 4000 series.