Running Windows software which are Installed through Boot Camp

Hi,

I saw a feature that Fusion could run Windows software which are installed through Boot Camp.

I would like to know if there are any differences in Performance, Memory Usage, Battery Life, Stability features if I;

1. Install Windows freshly from Fusion and run software (especially MS Office) in Unity View.

2. Install Windows and software on Boot Camp and run from Fusion in Unity View.

I am currently using MBA 2013 with 4GB RAM and 1.3 GHz Haswell Processor.

Thanks...