VPI 300 RPM vs 600 RPM Better?

I just hooked up the 300 RPM upgrade for my scout and I waiting for the no brainer improvements. Does it take some time to break in? So far it sounds restrained and veiled.
The 300rpm motor is not necessarily a better motor than the 600rpm as proven by the fact that many vpi users are split between the two. Many users cannot discern a difference between the two. Yes, motors do take time to break in.
The only purpose a motor serves is to maintain the correct speed of the turn table. It is out of the signal path. So I suggest you check the TT speed to make sure it is correct and stable.

Another way a motor can affect sound is the motor vibration transmitted to the turn table. That is the basics for the 300rpm motor upgrade because it is spinning at lower speed and vibrates less than the 600rpm one. So if the motor isn't quiet enough, you might want put a drop of motor oil in to quiet it down. The user manual has details on what oil to use and where to put it.

I think you will get better result with this approach than relying on some mysterious break in process.
No, it is just another way for Harry to make money, bless his heart. Harry is a master at the game of 'new', when nothing has really changed in ten years.
Silly me, I thought the 600 rpm motor was the upgrade???
In the ad they said quieter backgrounds. I am not so sure.
The 300rpm motor is quieter.

Try this: take the belt off the motor so that the platter won't move, lower the stylus onto the platter, switch on you amp and turn up the volume. Now switch on the motor and you should hear hum.

The hum will come and go as you switch on and off the motor. The hum isn't electrical, it is from the vibration of the motor transmitted through the table and shooting back up to the platter from the cone feet.

If you try this experiment with both motors, you will find that the hum from the 300rpm is much much lower.
Vibrations can be remediated in this regard. A moongel or sorbothane type pad can be placed underneath the motor pod - remove the rubber feet.

I believe the 600 rpm motor has twice the torque of the 300 motor. I have no 'vibration' problems. When I brush the record with stylus down on my Scout I notice far less speed recession than anything else I have ever owned, including rim drives, DD's and other belt drives.
I am getting too much vibration from the 300 RPM motor. I putthe 600 RPM motor back in, vibration gone. IMO, the 600 RPM is quieter.
I strongly suspect that the amount of motor vibration varies quite a bit based on the position of the magnets in the motor which I understand is not very precise.

Small changes in the phase of the motor drive makes quite a bit of difference in how smoothly the motor runs.

You can probably do this by tweaking the phase shifting cap value but the easiest way for me is to use a computer to generate the drive signal using an inexpensive frequency generating software.
@Tzh21y, The 300rpm motor definitely should be a lot quieter. That is the whole point of the upgrade. If it isn't, I think there is something very wrong with the motor you bought. I suggest you contact VPI and see if you can have it exchanged.
I went back to the 600 RPM
Be careful about putting the motor pod on a compliant material such as sorbothane. As with most things in audio there is always a compromise involved; pluses/minuses. For best sound, the motor should be as mechanically grounded as possible; IOW, not be able to move. Sorbothane allows it to move as the belt tension and it's own internal vibrations affect it's stability. You have to weigh the very real advantage of a lower noise floor against the advantages of absolutely stable mounting. Movement of the motor in relation of the platter has a significant effect on speed stability, dynamics, and introduces it's own kind of "noise" (image blurring). Choose your poison. I found that a thin cork sheet under the motor pod was the best compromise for me.
I've got my motor pod sitting on top of this EAR product:


It has dampening foam seated in between 2 aluminum plates. Very hard and stable and still has some dampening and isolation properties.