Many games tried to combine realtime and turn-based mode advantages, but none succeed. Things in Fallout Tactics are different. Of course, you cannot go away to drink some tea during your turn - the clock is ticking, but this is not realtime where things are based on reflexes and intuition. The engine was initially expected to be full 3D, but it appeared to be 2D like original one. There now some interactivity present in Fallout world - objects like barrels, tanks, doors, tables, etc.
Multilevel maps are available.
You can go upstairs to roof of building, significantly increasing your sight range. It is hard to find better place for sniper. You can access building basement any time. Game engine supports this process without splitting it into different maps. No more such things in Fallout Tactics .