I got my pre order wed, Thursday i returned it. My situation was a bit unique, i opened a new business line and wanted to give the s10 a try.
Its a fantastic device, however most of my complaints were with OS, fingerprint id was hit or miss, notificatiosn bothered me or lack theroff, i sometimes ended up missing emails or txt messages sent hours ago....just used to iOS i guess. Amongst other things such as i just prefer simplicity of ios layout and how fluid it is, and things just worked. I found android apps like instagram were somewhat less polished.
I ended up switching to the X. Was a tmo promo for new lines. Felt great within minutes. This is must be my fifth time giving android a try, not for me. And im an ex blackberry guy.
I recently switched to the iPhone - an XS Max - after using Android phones (and tablets) from their inception. I switched to the iPad almost 4 years ago and the adjective "more polished" is what I used when describing the big difference to me between Android and iOS devices and what drove me to the iPhone. I'd also say that iOS-based apps also tend to be more sophisticated than Android apps (recognizing that's a generalization).