My dillon beam has a metal base, I broke a lee by dropping it. I do have a Lyman beam that's quite old and it also has a metal base.
vette, I also have a Lyman 505 beam scale, and I do like it better than my Lee, but the Lyman's plastic base is annoying since it doesn't like to stay put, and the slightest bump will send it sliding across the table... if it had a much heavier base I would like it just fine.