So I was curious about getting the experience runes, so I bought 2 of them which give an extra 4% boost , and I am also using the mastery exp buff, which gives another 5.0%. Now that is 9% exp boost, but yet I lvl with everyone else. I see them as a waste of IP and have not seen any benifit from them. Do they actually work?! And if so why do I lvl just as everyone else. I asked lane partners how much exp they get per kill, and they are getting exactly as I am.

They do work, they just don't update the floating text numbers you see.

It's on the backlog to fix.

in my experience, the exp runes and talents only truly shine if you have a jungler and need to meet some xp breakpoint, or if you have a zilean on your team

maybe in the character menu it could have your base stat + item stat + rune stat = main stat