The GH1 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, Creative Movie mode (where you can adjust shutter speed and aperture), 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.
That aperture button invokes an interesting shutter-speed effect preview. Unfortunately, it only works in Program mode.