http://collider.com/star-wars-the-force-awakens-deleted-scenes-maz-snowspeeder-rathtar/

^This Link gives information about more dogfighting around Star killer base that was cut and more to the Rathtar Sequence (not sure if I spelled it right) There is obviously more to Phasma being put in the trash compactor and Star Killer actually firing on the Planets some sort of scene missing there.

I have not yet seen the ones released but, sounds like the x-wing’s going to light speed is the best offering seen so far.

I reckon the Maz scene will be good.

My bet is they are holding off for an extended cut.

But also obviously the whole knights of Ren sequence is being held off until episode 8 and the conversation between Rey and Luke is all shot for episode 8 by JJ already. They just decided to hold that for later in episode 8. So that accounts for the other 20 minutes. Cut on Purpose.

20 minutes cut speed up the film. So your looking at about a 10 - 15 minutes extended cut. of which you have seen around 5 minutes which will not be in the extended cut or atleast targeted to be cut.