As per the title.

In need of a new device after using the Galaxy S8 for 4 years now. Reason for upgrading is due to degraded battery performance, screen burn on the S8 and just to update camera tech I guess.

I always thought that when I do upgrade from the S8, I'll get the latest Galaxy device at that time. That time has come, and comparing prices and specs between the 2, my mind is telling me go Xiaomi. 

I am not familiar with Xiaomi phones at all and do not know the difference between Mi10 pro, Mi 10T, Mi 10 ultra. Slight differences on Gsmarena. I am basically looking for their top end phone. I do understand the Mi 11 is due soon. Will there be a Mi 11 pro/ultra? When?

So, in short, tell me about your experiences using the Mi Phones and any reason I should choose the Mi 11 over the Samsung. I've read somewhere that the Xiaomi Phones have ads all over the place, is this true? Please also comment on the camera of these phones as I'd like myself a good camera. Other essentials for me: neat and clean UI, good camera, I run MS suite apps on my phone often, OneDrive included. I mostly use Samsung native apps for email and calendar (with my outlook account added to the Samsung email and calendar app), MS apps and camera on my phone. A bunch of social media apps as well. 

Will a possible Mi 11 Pro/Ultra be similarly spec'd to the Galaxy S21 or better?