1999 - 2001, OutdoorPlaces. Com, All rights reserved OutdoorPlaces. There is no real major advantage to one or the other. If you have a left zip and a right zip bag from the same manufacturer, you can typically zip the two together. Unless you plan to only do summer camping, a sleeping bag with a hood is a must have option.
Hoods come in a variety of styles.
Some hoods are simply made of the shell material and stretch around your head. Others may have drawstrings so you can cuddle up until just your face is coming through. Others may be insulated and offer other features to help keep the rest of you warm. A storage bag helps protect your sleeping bag when it is not being used. A compression sack is usually made of a more durable, moisture resistant material.