Threads and mutexes are the most complicating things in computer science. I am always skeptical of new implementations until they've been used for several years at scale. Bugs in these threading mechanisms often elude even the most intense scrutiny. When Java hit the scene in the mid 90s it exposed all manner of thread and mutex bugs in Solaris. I don't want the fastest mutex implementation - I want a reliable one.
mutexes are far from the most 'complicated'. There are really not that many way to implement them (efficiently). In most cases there are best avoided, esp. on the read paths.
