Well you're wrong. I get free xbox games twice a month on 360, and have gotten some popular/high quality games. I also get to KEEP them regardless if I have XBL or not. That automatically beats playstation plus on like every system (I own a vita/ps3 and ps4). xbox one been blowing PS4 free games out of the water. I haven't even found a reason to have Psplus for PS4 at all.
PS Plus is like playing Russian Roulette. It's either Indie crap (which they been doing alot lately) or the occasional golden month of good deals for AAA. Like it was already mentioned you don't own the games at the end of the day (More like long-term renting as long as you keep giving Sony money) which is one of the edges XBL has. Both services "free games" deal though is pretty mediocre overall though.
Also MS has the same discount options and deal of the week. I've got plenty of games off of that also. But this wasn't about PS vs Xbox. This is about me wanting PSPlus to be more useful for me since I'm paying for it and it's hardly even being used.