In a vacuum, it's hard to get too upset - yes we played like shit, but we're not out and we still have a shot.
I think what really frustrates me is that it's the same story year after year in the knockout rounds of the group stage. No matter the manager, no matter the team selection, we always fall flat around this time in the Champions league, and I'm just not sure why. Every year we go into it and I think "this is the year we make some noise, we're just as talented as every team left" - and we come out and play lifeless and scared. So I think I'm more frustrated at the accumulation of the past 8 years rather then this result because we could turn them over at the Etihad (although I don't think that's likely)