the two are the same once you remove the spider - so both :).
Are you 100% sure, for the Rotor web site is Q-factor is not the same.
Rotor 3D = 148mm http://rotorbike.com/...ad/versions/3d24_237
Rotor 3D Track = 147mm http://rotorbike.com/.../track/3d24-track_62
Because I'm about to buy a Rotor 3D Track crankset, but should be able to use your power meter track when it comes on the market.
So I might as well buy the right cranks now.
My TT bike