The G1 offers a full set of manual controls, laid out--for the most part--in a logical and easy-to-use manner. In addition to the usual manual, semimanual, and preset (scene) exposure modes, the mode dial offers Panasonic's Intelligent Auto, a custom settings slot (to choose from three user settings options) and a place to edit your color, brightness and saturation settings.
I really like Panasonic's Q.Menu, which is a fast way to access all the most frequently needed shooting settings, but I 'm not as sold on the necessity of giving Film Mode--essentially, presets for color, saturation, and brightness combinations--such a prominent placement.
I do like the location of the drive mode switch, but don't like Panasonic's bracketing implementation. It's hardwired to presets, such as three shots at 1/3 stop increments and five shots at 2/3 stop increments, rather than allowing you to choose the frames and bracket separately. This is complicated by the fact that you can't choose full-stop increments. On the other hand, the virtual display it uses to select the center bracket exposure is very nicely done.
The G1 uses a traditional four-way-nav plus Set button for accessing ISO sensitivity, white balance, AF mode (user-selectable area, face detection, automatic, and spot tracking) and a user-definable function button that can be set to pull up settings for aspect ratio, quality, metering mode, intelligent exposure or guidelines.
That aperture button invokes an interesting shutter-speed effect preview mode. While useful if you're trying to figure out the best rate for stopping a particular motion or getting the most interesting motion trails, it's most notable for being the only way to get an accurate exposure preview on the camera. Because all EVFs and LCDs automatically gain up so that you can see the scene, you never really see the exposure; this allows you to.
Cameras with electronic viewfinders can be a major pain. In addition to the manual LCD/LVF (aka EVF) toggle, the G1 has an automatic sensor which can switch between the two. On one hand, I hate having to manually toggle; there's always that brief pause where you wonder why one display or the other is black before you remember to hit the button and I find it disruptive to my shooting rhythm. On the other hand, the automatic sensor, which is supposed to detect when you put the camera up to your eye, is too easily fooled. When I lower my arms to change settings via the menu, it thinks my jacket is my face and switches to the EVF. Grrr. It needs a manual override.
This innocuous-looking jog dial is my biggest pet peeve with the G1's design. Pressing it in switches you between exposure compensation and whatever your current exposure mode control is; for instance, changing shutter speed if you're in shutter-priority mode. While I like it in concept, the implementation needs work. It's too easy to press by accident. I frequently had to stop shooting to reset exposure compensation to zero when I had been trying to change shutter speed.