Dear Rloggie: Don't worry about that additional clamp weight, it does not any harm to your TT that btw is really good, what do you think about?
Now on topic. Through the years I already use several clamps ( along the vacuum ): Sota ( not only as weight by at normal reflex way. ), Basis, Callas, AS, MS, etc etc and I can tell you that with each one you have different characteristics in the sound reproduction. Right now the Jeweltone ( that its main build material is glass. ) with 800grs on weight works really fine and like me a little more over the other ones but as usually you have to try it and find which one works for you and your music/sound priorities.
Regards and enjoy the music.