Slim bogeys here. I wear a medium sized glove.
I get a better and more repeatable grip with them over the palm swells.
How's it feel in your hand with the stock grips on? Slims are nearly identical in thickness, just way more aggressive and less slippery.
To complicate this more, I honestly feel you can train your hands to get a repeatable grip with either model. The big thing is getting to the mag release comfortably (breaking your grip as little as possible, if at all) and getting your strong side thumb where you want it (near the safety is where i like mine since i used to shoot a lot of SAO) when you get the webbing of your strong side hand up into the beavertail.`