i have sonarworks installed and use it every day! it is a great addition to an already good studio place and helps me getting a good balanced sound.
BUT you have to be carefull! it is not a cure for everything, a room which isnt treated well will still have his problems (maybe a bit less on the listening spot) and there is not a single software that can make a poorly treated room sound awesome.
so first treat your room so that the biggest problems are solved and then you can go and grab a software like this to compensate.
the second thing is, if you are not a newcomer you have been mixing on your system maybe for years and you know from feedback and other devices, where you check your mixes, how it should sound in your room that it is balanced. if you install this software you have to learn your environment completely new!
my imidiate problems were the low end and top end, as the top end was too low in my room and the low end to hot. so the first mixes i made were more imbalanced than the mixes before, but now i am way more consistent as i got used to the sound.
last but not least, you cant get around listening in different locations with different gear! you will have to listen to your mix on other systems like without the sonarworks but for me the difference between the listeningsystems is way less than before using the sonarworks software.
thats my experience with it! great tool but not a cure for everything!