This didnt work when first downloaded and its working now.
I'll give feedback later.
edit, I have now played once and there was no pathing, I am rebuilding and going to play again. I dont know if this is an error your end or mine.
edit, I have now played again with the rebult pathing and considering the size and complexity of the level there seemed relatively few spots to iron out. Unfortunately I did manage to get stuck in the market, where not only is the pathing bad in some places if you jump into the market stand which is on its side, you cant get back out(admittedly I was attempting to find exploits whilst this happened)
My main criticism though is the lag, this level appears to have no separate zones and is one big lag fest full of BSP houses and giant emitters. It really is a mess in this regard. If you look at West London, its all static meshes and areas are zoned so that for instance if you are in the tunnel, then only the tunnel exists for the game engine to handle. With your level you are handling the whole level so you really need to learn zoning, which is good news really. I dont know what frame rates youre getting however you could easily make this level run smooth because between houses you can never see the whole level in one go.
Otherwise I would say that it could be great however youre looking at hours and hours to get this monster cleaned up, because its just so big and complex.
I like the rooftops although again there is a massive challenge in making this level hard and I can imagine there would be exploits not found. Its just so big and ambitious.