Both methods have their advantages/disadvantages. Bottling can be less expensive (bottles are free from recycling or beer-drinking friends), and can be cleaned and reused, carried easily to parties, given as gifts and fit in your refrigerator and require no special equipment to operate. Kegging your beer is easier than bottling because you only have one container to fill (and only one to clean). It allows you to force carbonate your beer instead of having to use priming sugar, and you can use a nitrogen/carbon dioxide mixture in your stouts to make them creamier (smaller, softer bubbles). Kegs cost $30-$40 used, $90+ new and require a gas bottle ($50), regulator ($50) and fittings ($10) and a faucet or tap ($25) as well as a kegerator to keep the kegs in ($450+ , or make your own). Awfully expensive, but terribly impressive!