Tangible Benefits:
By reclaiming your space, you fill find that you have more storage that you thought.
By managing your belongings, you will use your things more effectively.
By eliminating clutter and maximizing efficiency, you will save money by not over-buying stuff you already have.
Non-Tangible Benefits:
Maximizing efficiency means that you have more time to spend on more important things.
Being in your space will rejuvenate you, rather than drain your energy.
An organized space will save your sanity.