I finally got to handle a G15 in a Best Buy while traveling recently. I liked the size, since it compares size-wise with my G9. I too think a swivel screen would be nice to have, because I like it on my G11. However, the G15 screen is much easier to view than the G9 or G11, so I might be able to accept not having a swivel screen. My "whine" with the G15 is the "short" zoom range vs my G9. I used the G9 for most of trip this year, and enjoyed it once more. I do wish it had the high ISO performance I believe the G15 has though. Still cannot bring myself to give up the G9 at this point. I did use the onboard flash of the G9 more this time for the snapshots of grandkids, etc., and even used full Auto several times to include flash. The results are the kind of keepers you would want to remember the trip, and not worry about high ISO and no flash photo options.
Dennis