Apple hasn't added Grand Central Dispatch yet. Nor have they added OpenCL. If all you care about is the UI, the go Linux. You can change the UI whenever you feel like it. Sorry, but saying that the UI hasn't changed and therefore it sucks shows your little to non-existent knowledge about computers and technology.
Another example of your little to non-existent knowledge about computers and technology is that you (or whoever said that) claim debug code is the same as release code. Unless Apple is a dimwit with 3 year old programmers, debug code is NEVER release code. EVER. It's not even called debug code, but a beta release. The actually RTM release is much different. They clean up code, modify modules, etc. to RTM standards. Unless you have the actual retail disc or the gold master master DVD, you don't have the actual release OS.