Well, I not often play TDM but understood it. I think it is subjective things - I for example didn't manage with that empty room and that vent I asked earlier.
Lost huge chunk of loot. Very good city mission, smallish in size but densely packed with everything (I like occasional small puzzles and also - how those stories of locals are interwoven) but I suspect that loot goal is quite steep.
Edit. Sorry, didn't notice that loot objective was optional.