I don't think our United side in 07 08 would've beaten Barca the way Bayern did.
Barca in 2008 were just as bad as this team is now. They came third in the La Liga, which wasn't strong itself since Madrid, who won twice in a row from 06 to 08, were not getting past the R16 in the UCL themselves, being beaten by Bayern and Roma.
Even Hargreaves and Rio were saying after the Barca-Bayern game that they gave too much respect to Barca in 2008, something this Bayern team did not.
While Roma in 2007 were probably better or atleast as good as this Barca team, it is completely different to go out attacking against Roma as it is against Barca with Messi. Reputation goes along way when assessing how to play an opponent and we saw that in 2008.
You have to put context to this, they probably forgot but leading up to the Barca game, we drew with Blackburn away. This was our run of games;
April 19th - Blackburn away
April 23 rd - Barcelona away
April 26th - Chelsea Away
April 29th - Barcelona at home.
So we go to Barcelona away knowing that we have to go to Chelsea away on the weekend and cant afford to lose to them. As it happens, Chelsea beat us on the weekend and now we are on equal points with 2 games to go. The pressure on us and the situation is so different compared to Bayern this year.
It never gets spoken enough, but that Chelsea team were a bad game (from United) away from winning the league and a penalty away from winning the CL in 07/08.