Alright, a lot of these posts were tl;dr, so I'm sorry if I repeat any information/opinion.
First off, the ODSTs are supposed to be the elite soldiers. A lot of the speculation here is directed towards general military infantry using them, but this would really only be for Navy Seals or special Marines squads.
A point I tried to cover, which kind of justifies the cost.
Secondly, the weight problem could be simply solved by the addition of a relatively cheap exoskeleton, I.E. the Lockheed Martin HULC project.
The weight issue lies in that hard armor is always heavier than the bare BDU and kevlar vest currently in service. A serviceable ODST armor would probably weigh around 60 to 70 pounds on its own, simply because of all the titanium ceramic plates.
Third, HUD technology is already being integrated into the upper echelon of the marines to monitor the heart rate and location of their team, both on their visors and wrist units. Also night vision. No brainer there.
Basically, yeah.
And as for the armor, even if you don't want to use poly-carbides and titanium alloys, I'm sure most of you have heard of Dragon Skin bulletproof armor, layered ceramic plates that laugh at repeated attempts by smaller caliber rounds, which an elite stealth squad that would put this armor to use, not an assault unit, which is what most people are thinking of.
Well, yeah, but, Dragon-Skinning it would be a completely different armor concept. The ODST armor, which this is a discussion about, consists of several single-plate armor sections, not armor scales. Not that your statement isn't valid, it's just not very much in line with ODST armor.
Anything I'm missing?
Sith, the thing is, "militarily inferior" doesn't mean "no way to kill our soldiers". The band of insurgents that oppose the military aren't afraid at all of US soldiers, because the latter can't pinpoint them, are just as liable to get themselves dead as shoot insurgents, and are fodder for improvised explosives. Even our elite are ineffective. We don't stop a lot of them, and we don't even lower their morale. That's where the faceless killing machine sonuvabitch in bulletproof black armor comes in. You see this coming at you, not being slowed down by your bullets and explosives, and you will feel fear. And your comrades will feel fear. And everyone who hears about it or sees it will feel fear. And this fear will make you abandon your cause, for you know you will not win, because not only are you "militarily inferior" but you're lightyears behind that.
I mean, SEALs don't get sent to help with humanitarian aid. US Army soldiers, Navy seamen, Air Force airmen, and the like do. The SEALs infiltrate, complete their combat mission quickly and effectively, and get out. They don't have to be warm and inviting. They have to be good fighters with gear up to par with their mission. ODSTs are like SEALs. I mean, the soldiers and marines in Halo all have open-faced helmets or wear caps. It's only the elite, the ODSTs and the Spartans who wear closed helmets. (And a few police and pilot exceptions)
In truth there is a very real need for such technologies. Things that can save the lives of those who are fighting to end oppression and terror. The status quo is insufficient.
Eled: With a HUD, you would pay it varying levels of attention, based on your situation. In heated combat, you probably wouldn't pay any more mind than where the firing reticule appears, and making sure that is in the same place as the bad guy. Maybe the red flash when your gun is starting to click low on ammo. But, let's say the fighting is at a lull. You need to quickly get a figure on your team's status, your weapon's ammunition, your vital signs, et cetera. Why not have the HUD tell you? Just leave it all up there so you're constantly in the know. The beautiful thing about the human brain is, if you focus it on a single thing, miscellany just fades out of view. It's like driving a car. You have a tachometer, spedometer, odometer, trip meter, fuel gauge, oil pressure gauge, water temperature gauge, volt meter, clock, and sometimes, even a GPS navigation system. Ideally, you should be minding all of them, simultaneously. But, in reality, you only focus on the speedometer and tach, while driving, and only occasionally glance at the others. But if you got rid of all the others (like most cars with idiot lights installed >.>) you would be screwed when you needed that info, because there would be no way to get it. (Because your idiot light isn't telling you)
The way I see it, all of these technologies are very useful, but damned expensive.