I just can't justify buying hardware from a company that is so hostile to developers and hackers as nice as it may be.
You'd temporarily lose some hardware support (documented) while it's being worked on. But I'm not sure why you expect losing performance? This is running native code. Same binary will run the same on both systems (+/- the llvm version differences).
There is nothing inherent about running Linux that will require it be slower, in some cases it will/is even faster, but the lack of everything being fully supported does actually impact performance right now. It has been getting better with time.
Makes you wonder about how the rest of the system components will compare when they're finished.