Pros and Cons of Platter Mass

Higher mass minimizes wow and flutter because the greater mass provides more inertia. High frequency mechanical noise causes less audible flutter because the platter is so massive that it takes a lot of energy to accelerate and decelerate it rapidly in an audible fashion. Low frequency mechanical noise is also less audible for the same reason. Many years ago I had a budget table with a truly lightweight platter that would slow slightly when the needle hit a loud passage on the record where the bigger groove modulations would cause frictional slowing. This was audible as wow. My current heavy platter doesn't have this susceptibility. The single greatest drawback of heavy platters is, in my opinion, that they require bigger motors or longer spin up times to reach playback speeds. (Of course, they also cost more.) In extreme cases, you have to give them a head start with a shove from your finger.

Jameswei is correct, his answer is absolutely in accord with my own experience, and I have owned perhaps fifteen turntables .

My current table utilizes a 70 pound platter and must be push started, even though it is air bearing. No doubt it is the quietest, most speed accurate and lowest wow and flutter of any table I have ever heard. Not too surprising, considering the laws of physics.

Can't tell ya...however, I do know the pros and cons of hitchiking!

Fatparrot, does it include a guide to the galaxy?

I hope this doesn't qualify as a freak argument, but I believe the ideal turntable platter would be close to no platter at all (the low mass concept taken to an extreme). The platter serves only two purposes, first it provides a place for the disc to sit and second to impart the motion of the motor to the disc. Neither of these functions requires high mass. The functions that Jameswei attributes to the platter should actually be performed by the motor. To the best of my knowledge only two turntables have been designed along these principles - one by Ed Meitner and another out of England by Real Sound. I've heard neither of these turntables so I no idea about the quality of the implementation. I suspect the reason that there are so few turntables designed with minimal platters is the lack of suitable motors. Motors designed from the ground up to properly perform what a turntable motor is supposed to do and not rely upon the platter to correct for its failings.
Notwithstanding the above, I have an RPM turntable with a relatively high mass platter.