I'm not refuting anything with respect to the L3. The L3 is important and we both said that, I did with the gaming benchmarks and you did with Intel's massive lead in L3 read/write speeds. What you're dismissing, though, is that the HD4000, like the HD3000, relies very heavily on that cache, thus sharing it between CPU and GPU is likely to handicap it in certain scenarios -- for instance gaming, where they're both relying on the same L3 store. The L3 in Intel also works far more efficiently as far as reads/writes go, but Intel's approach copies the L2 into the L3 as it moves up a cache level. This is great for accessing it if you're speeds are synchronous (in comparison with AMD who has a very very slow asynch clocked L3), it also uses up more space to write the lower level L2 into the L3 store. AMD doesn't do this and instead relies on slower cache with essentially more "room" because it's L2 and L3 work independently. The core i5 IB's will have to rely on a 3MB cache that's split between both GPU and CPU as opposed to the 6(?)MB i7 that was reviewed has. So while it's 3MB theoretical room it's always less than that due to the L2 bumping up being stored in L3. What I'm saying is your "5%" figure is probably wrong, or you're pulling it out of you know what. I know what you're saying about cache, trust me.
What I don't understand is where you're coming up with any info about the i3. Thin air, maybe?