I can safely say That about Xiaomi redmi 4 4GB RAM have some major problem yet.
My Opnion-
The mobile got hang after two days of use. Needed to go to service center to get it’s software updated.
Found atleast 4 people facing display screen cracked issue. I wonder why gorilla glass is not provided for phone at this price.
Over heating problem is also there. I would suggest to go for another better phone of this range.