Apparently for "Hail to the Thief" there was a huge difference between the CD and the 45rpm vinyl (which you'd expect, from the mastering process more so than the format itself). Although whether
this is actually Nigel Goodrich...
I'm yet to hear them but I'd like to think the new 12" 45rpm versions are also mastered properly for the format, not simply cut from a release CD like many vinyl records are - you'd be surprised.