The first side is quite good , first ten minutes excellent and a good keyboard leadbreak at the end.After the first side the music is weakened because Wakeman seems only occasionally interested.I never liked any part of the second side. The third side is something of a favorite because it is so weird I like to play it loud at traffic lights with the windows open to shock all those people listening to the trash they put on the radio. It is my revenge. The song part of the 4th side is beautiful but all in all the 3rd and 4th sides contain too much jamming rather than solid material.
It is quite a creative piece musically but it suffers from dull lyrics and the sides are poorly structured so it comes across as a rambling mess.
So for me 1st side is best, then third , then fourth and the second is worst.
One other point is that John Anderson ( He may have been Jon at the time) says part of the third side is inspired by Atlantean music (as in the lost and never found civilisation of Atlantis). This shocked me as I never realised his powers were beyond our usual conceptions of time and space.So those on this list who think that the prog heroes are mere mortals need to rethink . Amen.