Panoramas look best when the subjects tend to be in the distance. Things up close, like deck railings, may look curved, and, as you noted, focus can be a problem too. I've noticed that indoors the pano function sometimes gets lost on bare walls or repeating patterns.
Something else to note, if you're doing a pano and don't want to do the full width, you can stop and tap the screen to end at any point. Also, you don't have to hold the camera horizontally. Holding the camera vertically and panning to the side will give you a taller image, although not necessarily a full 180 degrees.
