I currently have both S10e and S10. Had S10+ originally but sold it since it was too big for me. Jumped to S10e but felt too small so settled with middle S10. S10e is great phone if you are fine with the size and I know many people do prefer the smaller size. Not much difference in overall experience, though I do see occasional hiccups on S10e on certain animations, opening apps and few other places. Not very noticeable but if you have S10+ or S10 side by side it is slightly noticeable at least for me.
I'm planning to either return or sell the S10E because all I need is one Samsung experience phone. I have an iPhone Xr for backup, even if I need another android phone I would go for Pixel 3 or upcoming G8 or something else. Personally, don't see a point keeping two Samsung phones, instead have variety