boreas
"If it sounds good, it IS good." E.K.E.
From looking at each table the PL-300 would be my choice. If it doesn't have a dust cover I wouldn't call it a deal breaker. You should make contact to make sure. The reason why the PL-300 is better are:
1) 1/2" mount for cartridges rather than the P-mount on the PL-230.
2) Direct Driver rather than belt. Nothing wrong with belt but most likely it will need to be replaced if it wasn't already.
3) Quartz lock vs dc servo
4) PL-300 is probably better built. Heavier from what I can find.
5) Cheaper, haha.
I would agree that the PL-300 is the better turntable and for the reasons stated except one. The PL-230 isn't a P-mount.
I've had two PL-400s which is the full automatic equivalent to the semi-automatic PL-300. Very satisfactory turntable.
John