Hi,
I updated to 7.2.3 and experienced the following:
1. The phone was very warm and within half a day battery dropped from 100% down to 80% without using it only in standby mode.
2. Second sim not working properly. sometimes no signal and keep on searching connect and disconnect.
3. Touch screen was not responsive took about 30 sec to react.
4. Wifi was very very SLOW and most of the time couldn't be connected.
My solution:
Went to service center and requested the staff to downgrade to 7.1.8. Once done, connect to WIFI and update to 7.2.3. During this process, did not install any apps from playstore. Once 7.2.3 was updated, I did a reset and my phone started a fresh and all my problems solved.
Hope it helps.