Apple should probably employ someone full-time to support valgrind on OS X, just for the in-house benefits...
http://clang.llvm.org/docs/AddressSanitizer.html
It catches more stuff than valgrind, and only slows a program down to ~half normal speed.
It requires compile time instrumentation, but I'm usually ok with that.
In any case, several basic features of the previous version of Valgrind work on OSX 10.8/10.9, so I don't think it is correct to say Valgrind is useless on OS X.
It would be more useful if you explained the specific problems with Valgrind on OSX that force you to use Linux.
If you heavily depend on non-core tools, yes. Otherwise, though, for 99% of developers it was install-reboot-resume work — and the advantages of being able to test what your users use are significant as well.