Jack clarified several times - the Playfield is the exact same size as a normal pro/premium/le machine, but the cabinet itself is slightly smaller. Being not quite as long depth/length wise, and slightly shorter height backbox, by a couple inches. With the same size translite in the backbox.

Honestly this looks really fun. I think the raptor pen looks like more fun the the pen on the Pro... Trex seems cooler too.

And if they use t-nuts or other solid fastener solutions and don't just screw anything into the MDF, the MDF might actually be better than ply for the Playfield... It won't dimple as easily and won't show planking through the clear.