Well, that's basically the same question like whether speeding on the highway gets you faster from A to B compared to moderate driving. Unless you run full throttle all the time you will see zero difference. AE has too many bottlenecks, anyway and even if you work with 4k in Premiere, it rarely ever maxes out.
I guess the issue could arise especially when exporting
It could, but even then it remains an open-ended question. You can't circumvent technical limitations in CoDecs/ file I/O plug-ins, Adobe Media Encoder or on a quite general level other factors like drive performance that may prevent you from making full use of your CPU. So unless you can very specifically say "always want to export my 4k footage to YouTube H.264" using this and that setting, these things shall be forever ambiguous and open to interpretation. Different settings will simply behave differently.
I had the same dilemma and decided to go with the 5930K and 64GB ram. Why?
a) the 2,5x price difference does not translate to 2.5x speed difference in any software I use (AE, PR, C4D, Mocha, etc..)
b) more ram is always a good thing with the above programs (especially when working in 4K),
c) I decided it to invest the 2,5x price difference in a fast m2 SSD system/application drive and a separate SSD drive for AE disk cache.
Mr.K8, I’m leaning towards that choice as well and for the same reasons...