the dual is a big step Down in quality comparred to the luxman, but it is somewhat difficult to give you advice as you dont give much information about your system and the state of it servicevice.
what cartridge are you using? is it properly adjusted, setup ? is it a good match whith the arm on the luxman or would this be the place to look for better performance ?
are your amp in good shape ore does it need service/recap ?
same goes whith your speakers, are they a good match with your amp? does they need service/recap ?
are you listening to other sources such as radio, cd, streaming etc? and are you satisfied with the way that those sources sounds ?'
in other Words, is it only the vinyl playing that is lacking in your desired sq ?
i honestly do not think you will get better sound just blindly swapping turntables - you need to make sure that your hole system is optimised and go from there ;-)
maybe if you give us more info we could give you better advice.
best luck
paul