These are high for a camera in this price range, but not really noticeably slow in practice except for action shots. Given its price, however, its 2 frames per second continuous-shooting rate disappoints, and the camera simply doesn't work fast enough to keep up with kids and pets -- for still photos, that is.
Panasonic CIPA rates the battery at about 300 shots, which is low, but it seemed to last longer, and the rating of 150 minutes of video shooting is comparable to most camcorders.
Image quality
The GH1 uses a 14-megapixel sensor that lets the camera produce 12-megapixel photos
regardless of aspect ratio. While overall the GH1 renders high-quality
photos, the G1's strike us as being better, with fewer noise
artefacts at high ISOs and slightly better tonal reproduction.

As with the G1, the lenses we tested with it -- including the Lumix G Vario HD f/4-5.8, 14-140mm kit lens and another 7-14mm, f/4 lens, which isn't stabilised and not video optimised -- produce sharp images. There's absolutely zero fringing or bleed. With its latest revision of the Venus Engine, Panasonic seems to have tweaked the exposure and metering, delivering much better results out of the box.
Like its sibling, the GH1 doesn't render exactly accurate colours. But they're within the bounds of acceptability and certainly pleasing if you like them vivid.
Its weakest aspect is the noise profile. The camera is pretty good up to and including ISO 400, but above that streaks in the blue channel produce unwanted yellow streaks in the photos. This may be fixable with a patch at some point -- we tested a production unit with final firmware.
The 30fps 720p 17Mbps video is good in both bright and dim light, but as usual the 24fps 1080p quality is more of a novelty than a decent general-purpose shooting mode. The low-light video doesn't exhibit much noise, instead displaying some colour contouring. The stereo mic delivers pretty good sound, but the position on top of the camera in front of the hot shoe seems to make it especially susceptible to wind noise. The GH1's wind filter helps, but doesn't completely eradicate it.
Conclusion
What does this all the GH1's tricks add up to? The video shooting experience
is better than that of any current dSLR, but beyond its moments of
excellence, the still photo quality and shooting experience doesn't
consistently match that of cheaper models.
It's a new technology and a new product line, so inevitably the price is high. If you need to be on the cutting edge and are willing to pay a premium for it, then the GH1 certainly confers the cred. As long as you don't shoot sports or in dark venues, you'll likely be very happy with the purchase.
If you're simply attracted by the flexibility of interchangeable lenses with autofocus and depth-of-field control for video, we'd suggest waiting a few months to see if the price falls or perhaps to see what Olympus has planned for the future of Micro Four Thirds cameras.