So I used to agree with you, but I've done extensive performance critical C development at Facebook (memcached, a new thing we are about to talk about) and I have also done extensive performance critical c++11 development (our layer 7 load balancer for http) and I'd have to say that c++11 is the far superior option if you really, truly understand what the compiler is doing to your code (a huge caveat).

Unique_ptrs are a total game changer, and the ability to use closures and lambdas when you want to set a callback function instead of a function pointer with a context pointer you have to cast and decode is absolutely huge for readability. maybe we aren't getting every last bit of performance out of it that we could with C, but it works at our pretty ridiculous scale, so I think C might have been a premature optimization for us.