I'll willingly cop to being a recent fan. I think that is likely to give me a different perspective on new songs vs. old songs than a longtime fan. I won't say that either perspective is better, but I think it does mean that I'm more likely to view the new songs in a similar light to the old songs, just because I've been familiar with them for a similar period of time, while the longtime fans have been familiar with ACOS for maybe 20 years or more compared to 4 years for BAI.
That being said, I completely agree with erwinrafael about ACOS. It's a good first go at an epic, but it's flawed compositionally and structurally it is just not as good as the later epics. It's a really good song, no doubt. But this band has a lot of really good songs. For me, ACOS ranks in the 20s to 30s on a list of Dream Theater's best songs.
Breaking All Illusions, meanwhile, ranks #1. It's compositionally, structurally and lyrically excellent. I agree that it is a second look at Learning to Live, but it's not a rip-off. It feels more like a similar idea revisited with almost 20 more years of songwriting experience and maturity, and while Learning to Live burns with youthful excitement, Breaking All Illusions is a mature, confident composition.
To me, saying that a song that is 4 years old shouldn't be able to come along and challenge one of the band's classics is similar to saying that a prog band that's only been around since the late 80s shouldn't be able to come along and challenge bands like Yes and King Crimson. I understand why longtime fans wouldn't like a new song better than one of the classics, but I definitely think that a new song can be the best song. I'm hoping that my favorite Dream Theater song completes this coup. I'm hoping it holds on this round, and if it does, I'll be voting for it in the final and hoping for it to do the impossible.