Nice work Bryan.
The rule of thirds is something I work to a lot as my work is purely esthetic, so this is my prime concern.
John like the 50-50 ratio which also works fine. At the end of the day I believe being aware of the ratios is a good foundation to work with, however they can be broken successfully. I would just say if the proportions are broken then make it obvious, it will then generally look fine, it is when the proportions are too close but not correct that they eye becomes confused in trying to decide if it looks right or not, the conclusion generally being ' I like it but there is something not quite right'.
Just my thoughts.