From experience, get a good case (I use Spigen Slim Armor). The G2 is an awesome phone, the best bang for the buck, but due to such small bezels its main trade off is fragility. Even a small drop hitting in a corner will shatter the screen, as the plastic edge deflects into the screen before it rebounds on impact. Looking at the G3 I think its the same. Having said that, definately get a G3, LG always gives more/better features/hardware for lower cost than the other major companies.
(Stock ZVC Rom)
Past Devices: HTC Butterfly, HTC One X - Tegra 3, LG Nitro HD, LG G2x, Samsung Vibrant, Samsung Galaxy 3, Nokia 5800, Motorola Razr Maxx, Palm Treo 650