I've tried the Rega, Mission Mechanic and Zeta, the latter on an Oracle Delphi Mk 2. Surprised at all the dislike for the RB300 - it is still a bargain, sonically, but the Zeta is a work of art that should handily better it, They are rare, so finding one will be a challenge.
If money isn't a problem you can always just shell out for an SME V.
If money isn't a problem you can always just shell out for an SME V.