What games lag/disconnect for you? That sounds like the specific games you're playing, which is the same stuff people experience on Xbox live. Most games are perfectly fine playing online, but if you play GTA online for example and its having issues that's 99% of the time Rockstars servers fucking up and has nothing to do with Sony
As of now, you get more free games with PS+ than Xbox offers. It's also $10 cheaper. They are often newer or brand new titles, including a much bigger catalogue of indie titles. Games With Gold is improving, but it's not on PlayStation's level.
They both give out discounts as well and they are virtually the same in all other aspects so I'm not sure why you're saying Live is so much better since it seems Sony has the edge right now (not a huge edge but a clear one nonetheless).
Anyways, neither cost that much in the grand scheme or things wo might as well have both, that's the best way about it.