As far as what is or is not an epic, I totally understand the argument that songs like Metropolis or Learning To Live are epics. But to me, being a fan from 1992 (and yes, I know that Kev is as well), those were always among my favorite songs, but there was something different about A Change of Seasons - it was set apart, it was unique. It was an epic. And it was all alone, for years and years.
Then came Six Degrees, which was 40+ minutes long. I thought it definitely occupied the same territory as ACOS, so now there were two epics.
Then eventually came Octavarium. By anyone's definition, this is certainly an epic.
Of course, then came In The Presence of Enemies, which I guess belongs as well, though it isn't in the same league as the the other 3.
And I also understand why some people accept The Count of Tuscany as an epic. I'm still of two minds about that one.
But I will say that look back fondly on the time when ACOS stood alone, and there wasn't a new epic on every album. Now people expect them, and will probably be disappointed if there isn't a new one on the next album.
But anyway, opinions vary.