As I said, it's still early. Today is the first day I didn't need to perform any reboots, etc.Really? So far I'm seeing less battery performance & SOT on Oreo than my Nougat setup.
I'm not a benchmark freak but I do test when trying different kernels. Benchmark results are about the same though when using Xceed kernel on both O & N.
I'll freely admit that my "evidence" is more anecdotal, and I'm not the most demanding when it comes to SOT.