I have a 12 inch AO arm on my Acoustic Signature Storm deck and currently use a Transfiguration Phoenix cart. I have a possible opportunity to acquire an SME IV in 9 inch form. As far as I can see the effective mass of both these arms is the same so a change wouldn’t restrict the possibilities for changing carts. The other technical difference I think is the lack of an azimuth adjustment on the SME.

Does anyone have experience of using both these arms and/or be willing to comment on the differences between the two?