Well, GOP is one hell of an opener. Very progresssive, very demanding, very interesting. But apart from references to Tool, am I the only one who hears one huge Steven Wilson knocking on the door when the melodic clean vocals start (before you start collecting wood for my personal bonfire, listen to 'Trains' from PTs 'In Absentia' or 'Glass Arm Shattering' from 'Deadwing')? One more think I like about the new songs in general is the production, which sounds like a blend of Deliverance and MAYH (less crisp and technical than Deliverance, more moody and gloomy like MAYH), it is definately a sign that they did not abandon their old style in favour of Steven Wilsons perfectionism, which I really appreciate.
However, I would not yet consider GOP one of their best songs (there are far too many I still like more - which could change over time), and I also still really do like TGC! The middle part rocks just too foakin hard to abandon the song for it's overall repetitiveness. And I could imagine it works really well toward the end of a long album, where the attention span of the listener is already pretty stressed and this song marks 'the final lap' without being too complex for it's own good. Besides, Opeth already had worse near closing tracks (Funeral Portrait: mediocre, even more repetitive, Serenity Painted Death: never worked for me, dunno why, Karma: plain sucked).