It depends on what you want to use your PC for;
AES-NI will considerably improve the spped atwhich encryption happens. Most code will require a recompile to take advantage of the new-instructions so if you're using (e.g.) hard-disk encryption you will certainly get benefit from AES-NI. Just make sure you're running a recent.latest version of the software.
Turbo-Boot works well in many situations but if you run single-threaded applications a lot (and that includes MS Office) then extra cores will be powered off and the one running core will run faster. Its like "free overclocking".
Execute Disable bit is a security feature. Prevents code executing when its not supposed to. Cant have too much security...
I hope that helps.