As I said (here) I will try writing a quick review on the extended battery. Basically YES the battery does comfortably last 1day+ with the following settings
80% screen brightness
CPU OVERCLOCKED – min = 384 / max = 1152
Gingerbread based ROMS, i must say that with using any froyo it was a clear difference in battery life, that may have been the individual rom or radio ect but it cut down a good 11/12 hours life out of my average battery length.
If anyone wants any more info just drop a comment.