I've used it on two very different templates and was glad of the options in the back end to adjust the number of tweets shown and if the date should be shown or not as the sites have different tweeting rates, etc.
The module looks OK, but on one of the templates the "Follow us on Twitter" link started from the edge of the box. This can be adjusted within the CSS inside the /tmpl/ folder if you have FTP access but a /*note would be handy for newbies. The twit.gif can easily be changed to something prettier if you have access to FTP also.
Those two adjustments will not be needed for most sites, so I'm happy to give this module a big thumbs-up! Overall, it's a simple, solid module that works.