Compact Body Compact body of Pentax RZ18 makes it much easier to carry it with you all day.
178g This camera is so light that you can comfortably carry it around all day.
Environmental Sealings For a camera that you carry everywhere with you, being weather proofed is a big advantage. You will have one less thing to worry about.
18.0X Optical Zoom 18.0X Optical Zoom of Pentax RZ18 will give you a lot of flexibility considering this will be your only camera during the day.
Small 1/2.33" (6.08 x 4.56 mm) sensor Pentax RZ18's small sensor struggles in low light situations compared to larger sensor.
No RAW shooting capability RAW files contains much more color information compared to JPEGs, and gives you more room for post processing without significant quality loss. They provide wider dynamic range and option to recover shadow and highlight clipping to some degree.