With having to setup a clean laptop to go out of state to a funeral, I loaded Fedora 23 on the Lenovo ThinkPad X1 Carbon. Out of curiosity, I ran a spectrum of benchmarks when it was a clean install of Fedora 23 with Linux 4.2 and Mesa 11.0, then applying all stable updates including Linux 4.4.6 and Mesa 11.1, and then lastly enabling the Rawhide Kernel Nodebug repository for an early helping of the Linux 4.6 kernel on Fedora 23.
The results didn't end up being terribly interesting for this Core i7 5600U Broadwell laptop/ultrabook with these Fedora 23 tests, thus it's just this quick, one-page article for those interested and curious if there are performance improvements later on in F23 and you happen to be an X1 Carbon owner or with similar hardware.
You can find all of the minimally changed benchmark results from this quick weekend testing via this OpenBenchmarking.org result file. The Linux 4.6 Rawhide Nodebug kernel so far has been stable and working out fine on my Fedora 23 system, for those interested in not the performance but making use of the new features of Linux 4.6.