Hey, AADSAS gives you two types of GPA's one (with) that takes into account + and -. For example an A+ is equal to 4.3333, A is equal to 4.0 and A- is equal to 3.6666. The othe GPA w/o does not take into account the plus and minus. An A+, A, and A- all equal to a 4.0 and i believe this is the more important GPA statistic as it brings everyone to an even playing field from a variety of background colleges.
I think both are relevant. I feel if a school has a +/- grading system, then the schools you are applying to should take that into account and focus on your GPA +/-.