So technically there are a few AIOs that beat the best of big air by a few C. Still not worth it though. Only reason I see to get an AIO is if an air cooler won't fit, there is just too many caveats to them.
I really like air coolers as I agree there are way too many things that can go wrong, My personal favorite is the Be Quiet Dark Rock Pro 3 followed closely by the Noctua NH-D15 but I personally just don't like having 2 pounds of metal hanging off the CPU socket compared to maybe a quarter of a pound with an AIO that's supported via tubing and a rad.
To answer the OP's original question, It depends on the game, Your minimums may go up but your averages will stay around the same.
I tested Rainbow 6 Siege at 1600MHz and 2400MHz just to show the difference and you'll notice that 2400MHz gives a nice little boost to the minimums but that's about it, Average stays the same and forget the maximum scores as they aren't reliable at all.
I ran each test 3 times to make sure the difference was correct between the clocks.
1600MHz
2400MHz