When you push it down all the way, there is no noticeable lag. In the highest quality mode, you'll have to wait about 4 seconds before you can take another photo. Portrait, landscape, and night scene mode automatically choose the best settings for each of these situations. Above was an example of night scene mode, taken from the usual spot on Twin Peaks. There's a little noise in there, but the quality is comparable to the other 2 Megapixel cameras out there.
Autumn leaves, for example, requires hard sharpness, high saturation, and enhanced reds.
Fireworks gets you a small aperture, bulb shutter, infinite focus, and daylight white balance. If you want to make your own scenes, you can do that too. If you blow them up and look carefully, you can see the difference. I'm not sure of the cause for either. In aperture priority mode, you can choose from f2.8 or f5.6.