I still use an old program that does a great job of monitor calibration as a software only capability. Of course a hardware/software solution is superior but if you don't need absolute perfect color this is good enough.
SuperCal
It is far superior to Apple's Built in Calibration. (Even expert). Now my MB monitor has much stronger contrast and deep colors. It is going to vary by your eye and your monitor so make your own calibration and see for yourself.