Regarding what makes Williams special, this has been discussed in a few previous threads:
Computer Science at Williams has also been discussed in a few threads (probably on others as well):
http://talk.collegeconfidential.com/williams-college/1876869-williams-cs.html#latest
http://talk.collegeconfidential.com/williams-college/732891-computer-science-at-williams.html
I think it is useful to check out the types of jobs recent CS alums have landed, which is reflective of the strength of the department:
http://www.cs.williams.edu/people/alumni-directory/
The campus is dead smack in the middle of the most drop-dead beatiful natural setting for any northeastern college, not to mention a hot-bed for the arts (nationally-recognized art museums and summer theater festival on or very close to campus, among others), and a very charming, quintessential New England small college town. It is however far from any true urban areas (3.5 hours to both New York and Boston, over 4 to Montreal) and is a fairly rural environment, so it depends on your definition of “nice area.”