No question - Mark 3 unrefurbs or Mark 2s. Comfy seats, tables and decent overhead racks. I have a pilot bag style briefcase which fits nicely into Mark 3 and Mark 2 overhead racks and they have great seats, bags of tables and good views. The Third Rate Mark 3 refurbs are worse than Ryanair plus the pink seat top grab handles resemble a row of Mickey Mouse ears.
Voyagers, Pendolinos and Mark 4s cramp the shoulders because of the profiled sides, plus Voyagers and Pendolinos strink.
Adelantes would be OK if seats no so narrow, better room in overhead rack and no engine growling under floor accompanied by gear changes
Welcome to the forum stebbo and can I say how delighted I am to see someone standing up for
Mk2s▸ as they are good carriages. The New Zealanders also seem to think so as many have made their way down to that part of the world.