I use both. I do my stats through an analyzer every week. However I also get into the raw log file and just pick an I.P. and do F3 (Windows here) and follow it to see truly what page and when the I.P. jumps. It will also help you discover leeching, rouge bots, etc..
there are many different types of logs.. i think most coomon is -
first IP of visitng machine, then it is dATE, then it is GET method -that means what was requested, then it is size of filwe i think ,then it is refferer, then ut us agent (like mozila etc) and some other info..