Loading ALL new brushes into the presets folder makes Photoshop very "heavy" and slow after some time. So I keep a file outside of PS where I put in all the goodies I find but don't use regularly.

When wanting to use one of those (e.g. brushes) I just open my PS normally, go to the brushes options .... and there click on the little black arrow to the right. A menu will roll down and from there I can still choose "load brushes" and there I can specify exactly from which folder I would like to load which brush.

Hope that was 'understandable' and clarifying. If not, just ask once more, and I will explain further.