Both phones also use LG's Optimus UI, but the LG G3 comes with an updated version of it, with a new, cleaner look and some new features, the most notable of which is 'Smart Notice', which provides context sensitive information, reminders and suggestions.
Both the LG G2 and LG G3 have 13MP cameras, but while the LG G2 has a single LED flash and OIS (optical image stabilisation), the LG G3 has a dual-LED flash, OIS+ and a laser autofocus.
The laser autofocus allows the G3 to take shots quicker than the G2, meaning you're less likely to miss a special moment.
Sensitivity on the LG G3 has also been radically improved over the G2, so it's far better equipped to take sharper shots, and the inclusion of Magic Focus brings the now popular background defocus effect to the handset.
Both phones have 2.1 megapixel front-facing snappers and both can shoot video in 1080p, but the LG G3 can go one better and shoot in 2160p with the rear sensor.
Both the LG G2 and the LG G3 have 3000mAh batteries, but while you can remove the juice pack from the G3 it's locked into place in the G2.
In theory that gives the LG G3 a slight edge since it opens up the option of carrying a spare and swapping them when one runs low, but on the other hand with its QHD screen and high power innards it might be more battery hungry.
Right now the LG G2 is available from around £300 SIM free, or from £21 per month on a two year contract with no upfront cost.
LG hasn't confirmed exactly what the G3 will sell for yet but we're expecting it to be around £550 SIM free, so almost twice as much as the G2. Contract prices are likely to be similarly pricey.
While we'll certainly need to put it through its paces the LG G3 sounds, on paper at least, like a substantial upgrade over the LG G2. The screen is better, it's more powerful, has a slightly more premium design, an improved camera, a revitalised interface and a few additions like a microSD card slot.
It's a bit of a shame that the battery hasn't been given a boost as it was one of the best things about the LG G2 and we can't help but worry that it might not hold up so well when coupled with the G3's retina-searing screen.
Plus the LG G3 is likely to cost nearly twice as much as the LG G2, but it's no more expensive than most other high end phones and if you want a true top tier flagship this looks like it might fit the bill.
- Samsung might have a super phone of its own on the way.