I am partial to Canon cameras, and have a Canon 5D Mark II, 7D, G11, and SD900 point and shoot. I also shoot with a Sony NEX-5 for Kite Aerial Photography as well as Pole Aerial Photography. I also have multiple GoPro cameras. So, I have experience with cameras at multiple levels. If you're looking for something not as bulky, but gets similar image quality to a dSLR, then I would suggest an interchangable lens camera like the NEX models from sony. The APS-C sensors will get you the low level performance that you desire in a smaller body. However, lenses are still expensive. Since I use my Sony for aerial photography, I almost always have the 20mm pancake lens on there to get as wide as possible.
Since you brought up the G15, I would like to point out how nifty certain canon point and shoot cameras are because of CHDK. CHDK,
http://chdk.wikia.com/wiki/CHDK, is an alternative, non-obtrusive firmware you can run for many canon cameras to add functionality such as scripts, motion detection, intervelometers, etc. I use it in Kite aerial photography, time lapse sequences, and sometime lightning detection. If you want something portable, the G series canons are a bit more bulky than a normal point and shoot, but have the retractable lens to help keep it portable. The ability to create time lapse sequences with your canon would be cool when going on road trips with your tear.
Others have recommended the S100 as an alternative to the G series. Same sensor, smaller compact size without some of the manual controls. The S100 has GPS built in while the S110 has Wi-Fi built in, but are pretty much the same. I know of a lot of other photographers who carry a S90, S95, or S100 as their pocket camera becuase the quality is very good. Amazon just dropped the price of the S100 to $249:
http://www.amazon.com/Canon-PowerShot-S100-Wide-Angle-Stabilized/dp/B005MTME3U/ref=sr_1_1?ie=UTF8&qid=1355890971&sr=8-1&keywords=S100If you have any questions about my experience with either the Canon G series, Sony NEX series, or photography in general, let me know. Here are my credentials:
http://www.m2-photo.com/Epic/2012-Art-Fair-Gallery/23624404_NG5mn4#!i=1410143545&k=fZsDXM5