For any folks still using the GH1, I did a lot of testing to develop a set of stable patch settings for 720p AVCHD shooting. The existing patch settings, it seems, had zero testing in 720p or totally missed several key points.

I will simply outline my findings, so that you can create your own patch settings to suit your needs:

* Increasing the overall bitrate will decrease reliability while doing nothing to improve video quality or increase the recorded bit rate. Just leave it at the default 18 Mbps.
* SH and H modes are equivalent. Feel free to program them with different bit rates and switch between them.
* The GH1 codec accumulates errors over the length of the GOP. Thus you need to keep the GOP somewhat short, under 12 frames or so, to keep the errors from becoming visible. Shortening the GOP increases the recorded bit rate and decreases reliability. I settled on 10 frames.
* Using a GOP 10 frames long: no failures with the bit rate set below 27 Mbps; failures were produced with great difficulty at 27 Mbps; failures occurred infrequently at 30 Mbps, and easily at 33 Mbps. I settled on SH=27 and H=25.
* No differences in reliability were observed between a Transcend class-6 card, a SanDisk Extreme HD Video UHS 30 MB/sec card, and a SanDisk Extreme 30 MB/s Edition card. It would seem that the bottleneck is not the card, even though failures are shown with a card write failure message.
* Changing the overall bitrate 2 or video buffer size produced no change in reliability, recorded bit rate, or video quality.

On the GH1, 720p remains my favorite shooting mode due to this camera's lack of 30 fps in 1080p, and because there is much less jello effect in 720p.