Can I revert to F350L 10d from F350L 20b

I have LG G Pro 2 , F350L 10d and I am planing to upgrade to F350L 20b ( which is Lollipop I think). I will do that through LG PC suite, easier and allow easy back up.
My question is , ca I revert back to F350L 10d ( kitkat 4.4.2) or I can not ?
What is the main differences between the 2 of them?
Thank you in advance