Ages ago I dug out my Ainsty sewer sections and ran through a few very quick games to test out how the rules would adapt to the situation. The first run through was Stalingrad the second Berlin 1945 (just an excuse to test how good IR kit would be). Good fun and I'm planning to add this extra dimension to a bigger above ground game soon.
On how on with the pics:
The Germans advance in late 1942.
The Russians come up to meet them.
Advantage- German (and there is still a grenade to be thrown in).
Soviet Engineers with body armour.
Speculative Germans with IR kit.
The Germans take up their positions- after this point the quality of the IR kit meant it turned into a bit of a turkey shoot.