I don't know, I'm thinking they are probably about the same. Even though I'm trying both lemmy and kbin, I'm on a large kbin server and on a small lemmy server. I think that can make a bigger difference for the ignorant (me) than lemmy vs kbin. It can get kind of complicated to do some basic tasks, and I think it's good if these aggregators can make it easier to do.
For Kbin, I am liking the way they organize my feed, but I think you can customize your filter/sort on lemmy to do the same. Plus they have the android mobile app Jerboa, so I'm sure the experience for the feed can be good (don't have to keep resetting the filter the way I'm doing on browser [since I dont have an android phone])
Definitely feel free to make these accounts though :) It's been cool, like a big experiment to make these two accounts. I have one on lemmy.studio and kbin.social