TRATB is neither proggy nor an epic. I equate it to an extremely lengthy "Hallowed-ish, Flight of Icarus-ish, TROBB-ish" type song....
maintains a similar tempo throughout and flows as a single song from beginning to end within the Harris bassline bookends.
This is no criticism at all, it merely differentiates TRATB from Rime/SSOASS/The Sign Of The Cross/WTWWB/TBOS which are Maiden's epics.
TRATB is a top 10 song for me, it rules. They should play it twice each show next year. Perhaps even three times but substitute the third time with Wrathchild every second show.