Upgraded my L930 to windows 10 mobile directly from W8.1 update 2. Thanks to everyone for your tips, suggestion, feedback and reviews.
After several hours of usage, I'm really satisfied with this OS. I didn't do a hard reset. Still working fine.
What i feel:
1. The UI & font is really pleasing.
2. Found new and essential keyboard for me (Tamil).
3. Battery is draining as quick as it happened in W8.1.2. It drains at the speed of 6% per hour. In W8.1 it was max 3%.
4. Apps take time to load. Which is not a big concern.
5. It is not that much hot as mentioned in the previous feedbacks. Little heat.
6. I think, the smoothness will be improved in the best build.
7. I didn't had any issues in using WhatsApp, Facebook, calls, massaging. Camera in WhatsApp not working. But can upload.
I'm sure, i can use it as daily driver.
8. I miss the app"live lock screen beta" for it's theme although I've alternatives such as "lock mix" "lock screen changer".
9. File explorer is good. But while viewing a picture in camera roll swapping doesn't show the next picture. Have to close the picture and open next. That's quite annoying. Can use the default photos app.
10. Living images can be viewed directly on photos app.
11. All the shortcuts in notification and action centre is functional. We can customise only the last row of it.
12. Microsoft edge is also fine.
If found anything strange or new, I'll update it here.
Overall, I'm satisfied with the performance of W10. It is almost ready for the public release with some minor corrections.