HoMM IV Reference Guide.

Wanderer, regarding objects in the city and on the map – it's not all that straightforward either. For example, creature dwellings outside the city only provide a 50% bonus compared to those within the city.

He means various modifiers for movement points, armor, damage, mana, etc.
Sacred fountains, arenas, and so on.

And where is this? Who is streaming? Is there a link?

http://ru.twitch.tv/disciplesii - here are the streams; for now, mostly just I am playing with this thing :) Wanderer uses Migeko; each broadcast generates an ID, so you can find out his ID through ICQ or sometimes we post announcements in the thread (/forum/section/145/)