Yamaha's GHS (Graded Hammer Standard) weighted action has a heavier touch in the low end and lighter touch in the high end, just like the hammers inside an acoustic piano. The P45 is great for the aspiring pianist, practicing on the GHS action builds the proper finger technique for when the time comes to perform on an acoustic piano.
The P-45 requires very little space and can be easily moved anywhere in your home or even used for performance outside.