I am big ST fan so this could be of interest. I have the first seasons of TOS in HD (one on HD-DVD and one on BD). They were the ones redone with new SFX which I think is just fine.
The PQ is pretty amazing but given that they were filmed on 35mm film (which still exceeds HD quality), that's not surprising.
Not sure if setting it in the past is going to be an issue. After all Enterprise was set in the past also and was okay.


