They both have their accuracy problems, for instance awstats may count scrapers and bots looking for vulnerabilities as visitors. Google Analytics will not count people who have javascript disabled, or who have difficulty downloading the urchin.js file from Google’s servers. If you’re a marketing person, I would probably look at using Google Analytics. If you’re a webmaster who is also responsible for server security, then you may find a logfile analyzer beneficial. But remember, one is not better than the other and using one, doesn’t mean that you can’t also use another. Just don’t compare numbers between the two, you’ll drive yourself nuts, just compare the trends.

Anyone can link to file on your website and you’ll measure nothing!

Yes, that’s why I wrote:
“this method only reports on people clicking links on your website which are tagged with this code. If someone remotely links to a file on your site, none of the javascript web analytics packages will report on that traffic.”

Those bots that aren’t tracked in Google Analytics though info about their 404 vistis may be usefull too.

I tried to explain in the second half my post how to track 404 errors using Google Analytics. If you follow the second link, you’ll find more detailed info.

Reuben

Google Analytics will never show you the number of downloads. It will only show the number of clicks on the tracked links.

Number of downloads may be absolutely different from number of tracked clicks on “download file”. Anyone can link to file on your website and you’ll measure nothing!

Same problem with 404 websites… Many 404s’ are visited by bots. Those bots that aren’t tracked in Google Analytics though info about their 404 vistis may be usefull too.

Google Analytics is my favourite tool, but it still has its limits :-)