The best Mixing/Mastering software is the one that you have mastered and can use to its fullest extent,to manipulate it to get the results you are trying to achieve. in other words learning the program so you can do what you want to do when you need to do it.
Having that knowledge is key, there is a lot people that have so call Hot, Best, Crazy programs but only know enough to get by.
You want to think about the requierment for running that program on your computer, Ram,CPU,Tuning and dont forget the audio interface.
once you can rock a program the way you want to and develope an aproach, a fomula for working with that program base on the knowledge you have, you would probably think its the best, but remember even the so call best programs out there have its short coming.
You are getting opinions,suggestion,feedback,replys ect........and
no doubt this is what this forum is here for, but also bear in mind
that its all base on the equipment setup of individual members trying lead you in the right direction. its working for them but it may or may not work for you.
Hope this help you in your decision making process.