We find that the G3 is a physically simpler camera than the G2 was, taking more cues from the GF series than the GH series. The G3 isn't much bigger than the GF2 in comparison, in fact it looks like a GF2 but with a viewfinder and mode dial. The top plate is simple and less complicated than the GH2, and the hand grip is a subtle ridge, rather than the GH2's larger DSLR-like grip.
The top plate's controls have been drastically reduced from the G2, and that's one reason why the G3 is a smaller and lighter camera. The Mode dial has been retained, but simplified with less available modes. The Shooting Mode lever and AF Mode switches have been removed, most likely to save space; but the controls can still be accessed via the Quick Menu.
As a result of the simplification, the video Record button has been moved from the top of the camera to the back. We prefer it on top, as it was easier to reach with the finger not straying too far from the shutter release button. On the back it can still be reached using your thumb, but it can be a bit of a stretch. The Play button next to the video Record button is also harder to reach, especially if you're reaching with your left hand, as it's hiding just beside the jutting viewfinder.
The ever-useful iA (intelligent Auto) button is still there, and offers users a quick way to switch the camera to full auto mode. A brand new iA+ mode has been introduced, and lets you control aspects like depth of field, brightness and color. The camera shows a sliding scale when you press the control dial, with icons on either end illustrating the changes (the aperture and shutter speed changes are still displayed for more advanced users).
It's a useful change for when you want to take over aperture control in iA mode but don't want to keep going in and out of different modes. We do wonder if users will be confused as to why there needs to be two automatic modes, instead of just a unified option.