So you can still perfectly use your console, and the physical discs, since most of them have the complete build data on them. Sharing physical games has always been a big positive, as I have done so many times with numerous friends. As you mentioned, reselling physical games to recoup some of the cost is a positive as well. Most of my physical games that I have bought have been 10-30 euros cheaper that their digital counterparts. I might be wrong but, I think you cannot install new games if PSN is down.