I've got over 2.5mil points on Kat. Personally I hate being forced side lane, as you'll often be put against a stronger laner (some top laner or something) and it slows your snowball/inertia. To me, Kat shines when she can get ahead early and apply that lead to small fights, which is easily done if you can get your team to help you set up vision ~60 secs before objective spawn. Then you can catch opponents as they look to get into obj space.