Default How is LG when it comes to SW updates?

Hi guys, just a new LG user here. How is LG when it comes to SW update? Are the updates through OTA only or any PC or laptop application like Sony's PC Companion or Sony Update Service? And does LG carry the newest UI and apps they have on their latest phone like G3's flat UI carrying over to let's say G2 on a SW update like how Sony and Samsung are doing? Sorry really have no ideas when it comes to LG. Please bear with my noob questions.

Sent from my LG-D618 using XDA Premium 4 mobile app