I just updated my L830 to W10M this week (Last Monday in fact). Been good so far. But to have this experience, these are the steps I took:
1) Ensure that when updating, your phone is connected to a good WiFi (stable line. Speed is not an important factor tbh). Try not to use cellular data because the update is quite large (a few GB in size).
2) It is best to leave your phone connected to the charger when updating. The process drains your battery according to some users, but not for some. To be on the safe side, just connect your phone to the charger.
3) Do take note that when updating, the progress bar may appear "stuck" both during downloading the update and during the phone updating process (the one where the Gear icon appears on your screen). JUST LEAVE THE PHONE BE. The update is slowly but surely taking place, so have faith.
4) After the update is finished, do a hard reset and DO NOT RESTORE FROM A BACK UP. Yes, this might not be for everyone, but if you want to face bugs, then be my guest.
5) This is based on my personal experience, so I'm not really sure about you. But when I updated, I received the 10586.29 update instead of the latest .36 update. So after I did the hard reset and updated all the pending app updates, I then re-installed the Insider app, and after that the .36 update became available to download. Again, I updated everything to .36 but after the update I didn't do a hard reset. You could do if you want to, but for me it's not necessary.
So that's it! So far there's no major bugs, but there are some that is a bit annoying but ultimately does not affect your overall experience. Do ask me if you wanna know more about this, or if you have other questions.
P/S: After updating, your phone might get hot. This is due to the store trying to update abour 30+ apps simultaneously. So try to update the apps one by one. It will take time, but slow and steady wins the race.