Discussion about Heroes 4.

According to the "Troika" community, "fast" means reaching tier 7 within 1 week.

To be fair, reaching tier 7 in the first week only applies to the Stronghold. Otherwise, "fast" would be reaching tier 6 in the first week, I'd say. ;)
I largely agree with Nargott. Especially the observation regarding the grid cells on the battlefield. I hadn't really thought about it, but it's indeed a significant problem for planning. And, most importantly, it's poorly implemented, tactically speaking; it doesn't offer any particularly new tactics, just inconveniences...