The win against the Aggies looked impressive at the time, but as the season wore on it became apparent A&M has no defense to speak of. Currently the Aggies are behind Purdue, Northwestern, Penn State, Iowa and Wisconsin in total team defense coming in at No. 98 in the country. Johnny Manziel is a surgeon, but if your defense can't stop anyone it's tough to make a case you're a top team. A&M already has two losses and will probably end up with three after facing LSU in the second to last game of their season. Of course those losses (and defensive stats) are all taking place in the MIGHTY SEC, so they're glossed over.national perception folks.
Alabama's other "big win" came against Ole Miss, a 5-3 team that somehow managed to beat LSU. They are currently unranked but again "S-E-C", so that's not an issue.
Other huge wins came against 4-5 Colorado State, 0-9 Georgia State, 2-6 Kentucky, 3-6 Arkansas and 4-5 Tennessee. Impressive indeed.