A couple things that continue to bother me about this map:
1) All your windows are using the same "lit" skin. It seems natural to me that not every room in an industrial estate would be occupied, especially since industry hours are strictly 9 to 5 and this is set at night. I can only imagine it's set during winter months and in the UK because no where else would have such mild weather. You should change some of the skins, if only to break the monotony.
2) Every room and/or courtyard is littered with ramps or stairways. Height variation is good, yes, but it's like some spaces are a faithful representation from MC Escher's infamous "Relativity" drawing (Google if you must).
3) Said stairs are all set to a 2:1 ratio. Some 2:1 stairs are fine and occasionally aesthetics make them work as well, but it takes players longer climb a set of 2:1 stairs to the next height; and stairs are very difficult to undertake combat on and around (among other things they also make players predictable as they are forced to make linear movement). This is exploited primarily by demomen, snipers (especially huntsman) and less so, solly's. Ramps are fairly happy at any angle and depending on the aesthetic used to implement said ramp you can easily get away with odd or numerous ramps because rockets and grenades react in a more predictable fashion on them (they're flat surfaces). Stairs, not so much. The other thing is that stairs take up a lot of space. You don't have much open space for people to run around in, theirs either a low bridge going over the top or a ramp/stairway cutting across one or more flanks.
I find one of the reasons this map has a tendancy to stalemate is because combat, despite the multiple routes, is very linear. People running towards and away from each other with little opportunity to run around each other within a single space.