Basically just looks. You may get a tiny bit more air. Anything's better than stock though. Just be aware, they will not sit even from a front view. The left intake will seat higher than the right if you're OCD.
I don't believe you get more air with those. the amount of exposed filter is at or less than the stock filters because of the covers with only those tiny slits to expose them. More just for looks with those.
They also don't fit with the OEM crash bars if you ever plan on getting those. I had a set of the spike filters on mine and couldn't tell it made a bit of difference in the performance. After a while I wanted my crash bars back and took them off.
I have had them for many years and they are fine to me. The biggest issue is make sure you buy ones with the washable filter. You cannot get a K&N replacement anymore. I ended up having to buy some replacements from China.
They don't fit symmetrically on the bike. When looking straight down, the right one is about 4" forward of the left one. This is because of where the air box tubes come out.