My general rule of thumb is to avoid gear that's out of a stereo manufacturer's wheelhouse. Sansui receivers and amps are great, but not so much their speakers. Pioneer and Kenwood, same thing. KLH and Advent speakers are great, not so much their stereo gear. Obviously it's not garbage, but you know what I mean.
Marantz turntables are not garbage, again, but they're not great. For the price of a 6300 you should be getting either a full manual high-end table like a Thorens or a full-auto high-end table. The 6300 is semi-automatic. It is full of crap that breaks down--all those stupid microswitches are just the start. The motor has a board INSIDE the motor housing, and the caps and transistors on there should be replaced, or the table can have problems keeping speed. I sold a 6300, fully redone except for that stuff, and voila, six months later it's having speed issues, and I have to rip the whole thing apart to rebuild the motor board. There's more circuitry in the 6300 that can be recapped, but the motor board is something else.
Give me literally ANY turntable over the 6300, except for reselling, in which case I'll gladly take the 6300.
However, these are very expensive tables, despite the fact that they suck in a lot of ways. Why?
Well, people are suckers for Marantz gear. This we know. If you already have the high-end Marantz receiver, or an amp/preamp/tuner, then you may want a matching turntable, and the 6300 is the high-end one to get.