Thats even slower for content creating professional apps use than 6/8-core or the Skylake i7 iMac.
Just to clarify, that is entirely wrong. In actual benchmarks, the 12 core is as much as 85% faster in content creating professional apps than the 6-core/8-core counterparts (cMP). In apps like Premiere, blu-ray exports are 40% faster, blender almost 85% faster, AE exports are about 50% faster, and resolve deliver speeds are about 50% faster.
For example, if you're a heavy logic user, the 12 core mac pro completely outperforms the 6700k, it's not even close. The 6700k iMac caves in at ~110 tracks, the 12 core mac pro can handle ~190. The 12 core Mac Pro classic even came in at 57% faster than the 6700k in AE CC 2014 benchmarks.
The more accurate statement would be, "dependent upon the app." Because in most popular content creating professional apps (especially video related), the Mac Pro 12 core beats the 6700k. In consumer apps, non-efficient multi-core apps, the iMac will be faster. But then you're also stuck with the low-end M395 graphics card no matter what with the iMac. Once you're used to a card with 6gb+ VRAM, there's really no going back. You'll start finding limits you didn't even realize with 2gb permanently on the iMac's M395.
Overall, it really all depends on your needs, but for most 3D/video/graphics related apps, the MPc will be able to win in most categories. If you're a jack of all trades, or simply have diverse interests, the Mac Pro is nice, since one computer can cover all of your needs. But for lightroom and photoshop, the iMac will be great.
