I have been a smartphone user for almost as long as I have used a cellphone. As a user, I have evolved over these years. Most of my smartphone experience has been with Symbian (95%) and Windows Mobile (5%).

Planning to move to a Nokia Windows Phone in the future, these are certain features I am used to, which I find sadly missing on Nokia WIndows Phones
Notification LED: Its an LED on the front panel of the phone which blinks periodically whenever there’s a new Missed call or SMS.
For me, this is highly useful because most modern smartphones don’t show anything on their screens when in standby mode and you have to press a button and go to the lock screen to see whether there are any messages or missed calls.
Windows Phone supports this for Missed calls and voicemails only, not for SMS.
Nokia Windows Phones don’t have a Notification LED at all.
Profiles: I prefer to use different profiles when I am at home (Loud Ringer, no vibration, email alerts), when my phone is in my pocket (No Ringer, vibrations, no email alerts), when I am sleeping (No vibrations, low volume ascending ringer , no email alerts, calls only from family members) and Silent (No notifications at all).
This is something I have gotten used to such an extent that I felt terrible when I had to use an iphone for a week.
Windows Phone does not have this functionality natively at all.
Without these 2 features, there is no way I can buy a Nokia Windows Phone.