This method of reproduction is the most common for large numbers of copies.   A paper plate is made from your copy and hundreds of copies can be run from it.   The only drawbacks are not in the method itself but rather in the limited abilities of the person preparing the copy for the printer.  Usually, offset printing is employed on "camera ready" material.  These drawbacks are also true as mentioned above for photocopied material.

Camera ready means that the printer does not have to anything to your copy other than make the printing plates and print the newsletter.  Given acceptable camera ready copy, drawings and photographs, a good printer can turn your editorial efforts into a work of art.