My personal opinion is the Note 10 plus. 256 or 512 option. The S pen is phenomenal (at least to me). The camera's are great. I have both devices, my first choice is the note!
If you don't need the gimmicky s pen get an s10 plus. If you think you're gonna use the pen ever get the note 10 plus. If you need more info on the s pen go to YouTube.
They are both fantastic, solid flagships phones. It isn't so much a question of which is better but which would fit your lifestyle the best. If you use your device for a more work and management lifestyle then I'd recommend the Note series. If that's not the case, the the S10 would be a great fit. I have the S10+, upgraded to it from a Note8 and I don't regret it. It's really all personal preference.