I could see Battle Dress troops being urban combat specialists. They'd be the "tanks" of that environment, the real tanks being both overkill and too easy to kill. They'd be able to do the walk through walls trick, either literally or through not worrying about their own breaching charges, and just treat the environment as a 3d cube and make their own roads. And they could use gas and/or flamethrowers with built in protection from their own weapons.
Interstellar force projection would prefer Battle Dress; home defense might prefer the hi/low strategy already mentioned. The invaders knows they'll be outnumbered in almost any planetary invasion or intervention, even in a large ship universe, plus they're already spending credits for transport and control of the gravity well, so you might as well aim for outgunning the other guy. Unless up against a population both low pop and lower tech they'd then specialize in decapitation strikes, command and control, or high value supply or manufacturing rather than fighting armies in head on battles. Come to think of it though, Heinlein got here first, so not an original thought.
Keying off of Dragoner's idea of bicycles, they might have dedicated powered bikes. Maybe open frame grav bikes at the high end, but I'm thinking more of ground effect bikes or rocket sleds. Something fast, easy enough to refuel/refurbish when recovered, but still cheap enough to be treated as expendable.
It might be the Starship Troopers nostalgia, but I picture a military fielding battle dress including a missile rack or other heavy weapon option as standard. They've got the carrying capacity, they're already both armored and a target without it, so why stop at just a gauss rifle? But they might well not issue ammo depending on mission.
But quite possibly the 200,000 cr price is for partially de-milled suits. In which case carrying around the best rifle you can find is still pretty good.
An important question is what are the counter-BD weapons and tactics? You know there'll be something. Just rpgs with TL-appropriate warheads? I don't know of any rules for single-shot, burn-out-and-throw-away PGMPs, but maybe something could be worked out.
Most of any conventional fire team(5 or 4 men depending on the unit and nationality) in current western military units have mostly riflemen helping carry components to support the one or two man-portable "heavier weapons" in a team.
Things get interesting in non-Western forces that have tried 3-4 rpgmen with one rifleman for perimeter security.
This could be one approach to anti-battle dress tactics for lower tech or poorer forces. Everybody gets an rpg and a carbine, told to spread out, and wish them luck.
Then for the battle dress forces, BD as squad support weapon for a less armored infantry force is one approach; all BD heavy hitters circles back around to Heinlein's marauders.