LG G2 is a fine handset - we did think that LG had killed the IU to death, however there are some great new skins / launchers out there that hide all of the damage LG have done to an otherwise superb handset.
Again the issue of lag is there and isn't quite buttery smooth as the HTC One or the Sony Z1, we found that reducing the amount of widgets stopped some of the lag, but we thing its just a tweak away from being fixed.
Find a decent case for it, its not slippy but protecting that back button will be important, we are trying a few out to see which is best so will update when we find one, the LG flip case is 'ok' but the window on the flap is a little well, crap - something copied from Samsung that LG shouldn't have bothered with.
We did drop the handset a couple of times by mistake and glad to say both times it came out unscathed, once into the pavement and the other onto a wooden floor.
So build quality, good, camera, good, UI suspect but the overall experience is - well, good to superb ! In many ways the handset is just a whisker from being brilliant but LGs fascination with keeping up with the Jones's means they loose their own personality. Maybe they need to stop snooping on the neighbors.