rp3 and rp6 have the same 303 arm. the only diff of the 6 are rigid braces, slightly heavier glass platter yata And a p9 footer. subukan mong mag thump sa floor or sa TT stand kung may vibration. do it on both table. sa rp3 merong feedback hindi ko lang alam sa rp6 kse iba na yung isolation footer nya. but if you can have the wall mounted TT stand ng rega, just like doc endrick wala ka ng problema, just get the rp3. Btw, anong cart ba ang napupusuan mo pong ilagay on your planned TT?