Under the circumstances I thought it was a good performance. Muller perhaps showed his inexperience with giving away the penalty, but on the whole I think he's a really impressive young defender and the more he plays, the less likely errors like that will become. Brown also seems to be really growing into the team the more he plays, and I'm glad we put him into the back three to allow Rooney to play in his best position - hopefully we've seen the last of those two playing the other way around. As @Radford 72 says above, we suddenly have a lot of competition for places at the back and that can only be a good thing.
Also think MOH deserves a shout-out for the work he's put in this season, which was rewarded with a terrific goal. Just a pity we couldn't cling onto that lead.
I know Eetu didn't get long on the pitch but I thought he looked potentially very impressive - eager to get stuck in and confident enough to try that outrageous overhead kick with virtually his first touch (and it wasn't all that far away from hitting the net either).
I would like CD to be a bit more pro-active with his subs though. I feel other teams are changing things against us and then we end up having to be reactive. We really went for it at the end of the game on Saturday but it took us a while to make that shift.
On the whole I remain positive about the way things are going this season, despite some fairly baffling negativity on here over the last week or so.