Let's take for example an society that dwells in a jungle (75% of the world is jungle). Now, how would this civilization be able to develop and use powered armor and battlesuits efficiently?
As we saw in modern wars, terrain is murder on vehicles and logistics: Vietnam for example: the jungles took a heavy toll on supplies and made it difficult for vehicles and even troops to move about (well maybe not so much for the Viet Cong since they were better skilled in that environment).
So I'm taking that into account. Oh and the powered armor is very similar to that of the ones used by the Spartans in Halo, but isn't powered by nuclear fusion!
Some things to add: The armors are used by both elites and rank and file (the elite use more advanced and better armed and armored versions)
The armors would be used in both in the jungles and urban combat zones.
The armors would be used for defensive, offensive, and special missions (Delta Force level missions), so there will be variants used for different purposes.
The civilization understands that warfare can damage the environment and that nature sometimes damages itself. Of course, they're not going to go so far as to use flamethrowers and handheld nuclear grenades!