Complaince of Rega Carts?

Does anyone know the complaince figures for any of the Rega carts? Rega seems to basically take the attitude that "they work well in our arms" and that's it.Have a recently acquired RB-600 and would like some idea what carts would work well with this arm . While almost everything in a cart is being used and enjoyed by someone in a Rega arm - would like to be able to anticipate getting a reasonable LF resonance match.
Does anyone know if any of the actual lab test mags has ever tested one of the Rega's and published a compliance figure for it? Stereophile maybe ??