Whatever little FPS gain you get in gaming is negligible to the facts that AMD Ryzen's are higher performance, better multi-taskers, better ROI and cost-effectiveness, upgrade path to Zen2 next year.
Besides with the on-set of RT with Nvidia and other existing advanced GPU features like Asynchronous Compute and HSA with the Radeon, once developers start leveraging multi-core CPUs to their fullest, AMD would be a clear winner.
A faster single-threaded CPU is merely a sad patch fix to the actual root-cause of inefficient programming of DX12 titles and the CPU-GPU bottleneck which is solved by AMD's HSA and Asynchronous compute.