Google allows almost unlimited space to talk about what makes you so special. You can list brands, policies, locations served, types of clients, categories within your business, certificates, specialties, menu items, amenities, distances from land marks, famous clients, product benefits, and so much more.
Google Places has set this section up a bit weird in my opinion. You have two sides that creates something like a data base. On one side you list the general category and on the other side the attributes. They offer such suggestions as Parking on the left with free or street or metered as choices for the right.
I would be more inclined to have something like Located close to: on the left and bus transportation, bicycle friendly streets, San Francisco International Airport, the 10 and the 405 Fwys, other entertainment venues, etc. on the right. Or Major brands carried: on the left and a listing of those brands on the right.
There is no clear cut evidence that attributes help outside of the listing. However, information is key with Google, so it has to be a benefit on the listing. Moreover, it clearly has to be helpful in giving potential clients the info they need to decide to use you.
