Any thoughts on a solid hickory platform under my tt

I like solid maple.  I do not know why, but it is very popular.

I am not sure either. But I guess of the inexpensive woods it sounds better in most cases. Cherry, as an example, would probably cost more let alone Brazilian rosewood, cocobolo or African blackwood.
Even Michael Green who is an advocate of resonance control tunable speakers and rooms used to make Justarack racks with thick maple shelves. Mapleshade does this too.

All hardwood is nature's ideal dampening material.  It can absorb and dampen vibrations coming up from the floor.  

I would think the reason why maple is the most popular is that it is readily available and the most cost effective.  So its used the most.  And we have no shortage of it here in N. America being a renewable resource. 

I think there is absolutely no way to predict the end result without trying it.  Some tables, especially the Linn, are tremendously affected by what they sit on and others are not.  Plus, it's not about damping per-se.  It's about what your ears prefer.  That's why some people prefer not to use record clamps - they feel the sound is too dead without the little bit of resonance created by an unclamped record.  IMO, worry less about damping and more about what sounds good to your ears.  Good luck. 

Charyo
i was just curious , i have a vpi classic jmw 10 and a micro benz / ace also