Pros: Camera: Front camera is awesome, Realme gives you a premium front camera on a mid range smartphone. It blurs the background and gives you a better portrait mode than rear camera. Front camera gives you a bright and clear picture even in low light without requiring a front flash.
Battery Backup: It has a decent battery backup, im using this mobile for over a week now and I didn't find the battery to be disappointing, for a normal usage it lasts for 1.5 days easily and on heavy usage it lasts for 1 day.
Performance: It has a normal performance, it will not disappoint you but yes it has an average performance not too fast but till now it never gave me any problem in terms of performance.
Looks: This is the major reason why people would prefer buying this smartphone, believe me U1 has premium built quality, attractive shining bright colours and no one can say that its a mid range smartphone by its looks.
Unlocking: This is the best thing which I loved about U1. Face unlock is the best it also works in low light, I have used oneplus 5t and face unlock is the same on both the smartphones.
Everything is outstanding at this price.. Believe me you'll not get all this on a different smartphone for this price.
If I compare, what vivo is giving for 21k, you are getting those features in 12k (Looks, camera, batter life and other features) If you are looking for performance please purchase oneplus, it has best performance in the market.
Cons: I dont wish to mention it personally but just want you guys to know that it doesn't have fast charging.