Assemblies instead of groups?

[Mike L Sealander]

Are Assemblies better than groups for, say, a collection of chairs and table?

[damon.sidel]

Even more questions about assemblies:
What are the benefits of assemblies?
Why use them at all? Examples would be great.
How are they different from groups?
(I use groups a lot... too much... like for unit types in a residential building, window configurations that are repeated from floor to floor, floors+railings that are repeated on multiple floors.)