My 2012 2.5i Legacy has excellent forward lighting. Next to our two generation 2 Legacies, it is a minor miracle.
There are many other issues between the 2012 and 2013 models that you may wish to consider. There will be a new FB engine, and a new model of the CV transmission, and other changes. Depending on your views concerning being the test bed for newer technology, your decision will be an interesting one...