I have two 650's, the first one didn't have a strong mount, just solidly mounted to the bench. The second one came with the strong mount so I set it up with it installed (as Clock suggests, check your ceiling height as I had to shorten the brass feed mounting tube & feed tube to fit). I reload while sitting in a chair and ended up removing the strong mount as it was un-needed & made it more awkward to operate (see whats happening in the operating table). If you stand while reloading the strong mount may be of benefit but otherwise I don't see the point in having one. I just mounted bullet trays directly to the bench instead of the mount.
One thing with the second press that I did find that I liked, it came with the "optional" roller handle instead of the basic ball handle supplied with a kit...It would be well worth the extra few dollars.