So, because magic exist, let's have teleporters? I mean, those aren't realistic. How about some time travel too! And let's have aliens visit with manatech wonders of the future! Just because a facet of the setting is fantastic, doesn't mean you should throw the realism of the 'mundane' part of the setting out. It's still cyberpunk at the roots.
also means we don't have to pick one thing were it now HAS to be realistic.
(the next few line are not to be taken too seriously)
Not to mention there's actually a Spirit/Pixie power that lets you teleport between earth and your home dimension, so there's that
And corps are teleporting teams to other dimensions to find valuables(Market Panic).
And we also have the advanced nanotech/ware by aliens now that the monads are here(Market Panic). Which are kinda alien, being AIs and all.
And spirits are technically aliens, and they help people with magic, which is a science.
Got me with time travel though.

Nobody has actually put a price or availability on it, and even then people will find a way to get it. And what about civilian loader models with less armor and aren't forbidden? What about taking one of those and up-armoring it? There's plenty of opportunities out there. Saying it isn't feasible for 'runners to use/own isn't really an option yet, and I bet if rules were made, 'runners would find a way.
4ed also has tanks and nuclear submarines, don't think many people saw em in their normal games. And why would there even be civilian models, nobody talked about it so far and thats what drones are for.
(then again, according to Chrome Flesh, people are actually working on ExoWare that does just that, so what do i know)
Your whole point was that giving agility bonus to that armor would make ware essentialy unnecessary, and completely unbalance the game, which won't happen when it cost a mill and has an availibilty of 26+
Not to mention you completely ignore that you cant just always walk around in that armor. Have fun trailing someone in the sprawl with that thing on. Makes it pretty hard to be inconspicuous in a crowd.
Sure the Super Munchkin player will find a way to get it or maybe you're simply playing a military campaign, but the average shadowrun player will never get that thing unless his GM uses it in a campaign.
Heck most people don't even use the normal military armor.
Oh, I saw your 'penalty' bit. Like I said, it didn't deign a response. To elaborate, because you're saying the armor would have bonuses to negate those. Absolutely ludicrous. How would it being faster really help with stealth? You're still big, hulking, covered in servos and pneumatics, weighing perhaps a hundred kilos more... I would not provide ANY bonuses to stealth, and apply more penalties if you're moving (so standing still with ruthenium polymer would be a decent tactic). You ain't going to be quieter in one of these suits.
As i pointed out, it's about not being seen, i can get past guards because im faster. For example: a small time window were a certain area isn't watched.(The guard turned around for a time, or the other patrol isn't there yet) Then it helps stealth. Of course if you're running around on a metal grate right next to guards, you won't even need to bother with a check. But yes speed helps with stealth.
And since you talked about Halo, Master Chief doesn't seem to have any problem being sneaky in that armor of his(at least in the first game, didn't play the others).
So, your super-suit should have super-quick grabbing too? And some kind of algorithm to make finding spots to grab easier?
The suit helps with speed, i never said anything about super grabbing, if you move faster, you can grab new ledges/spots faster, which makes climbing faster.
Thats why the difficulty of the surface is a different modifier.
Maglocks require the tools of the trade, which doesn't always mean you need small fingers. A sequencer or passkey doesn't need you to break into the casing.
Sequenzer and Passcrads only apply their rating, which has nothing to do with agility. So any agility bonus doesn't matter.
Those multiple dice are very powerful, yes, especially since you're shooting 'bad stuff.' That is the most unbalanced aspect of it. You need a smartlink implanted to get a similar bonus just for shooting, and these would apply to ALL Agility rolls. Stealth, all weapons, gymnastics, those are some of the most used rolls in the game. They incorporate hitting (and thus hurting) the enemy, hiding from the enemy and evading the enemy. Those are some of the most important rolls for meat-body interactions (besides some of the Intuition-based ones). There's also still no consensus on whether or not it would stack with your own Agility augments. It isn't internal, so if I picked up Muscle Toner 4 and a suit that had a +4 Agility, does that mean I have a +8 to ALL Agility rolls?
But it doesn't give them a better chance to hit (or the damage inherent from hitting with better degrees of success, or the benefit of more dice to spend on Called Shots) if there's no boost to Agility.
The guy in the Armor will be the streetsam, if that guy doesn't manage to hit his precision limit when shooting even without the additinal +4 Agility of the Armor, he's had bad luck. Or needs to rework his build.
Even without the +4(and that if you even go so far as to use +4 agility, i was always thinking more along the line of +1/+2, and yes i didn't say it, my bad) any decent streetsam will always pull all this stuff of.
Edit: Also the Attribut Boost limit +4 still applies(unlike strenght we don't have a 4ed ruling on that one so lets just say it does)
On the other hand, even without the Agility/Strenght boost, the armor alone is so strong, that anything the GM has to throw against him is incredible lethal.(or direct combat spells, where the +4 Agi doesn't help either.)
Hardened armor basicially results in no damage or instakill.
At the end:
These armors are useless in a lot of situations because they draw ALOT of attention, and if they appear the agility bonus ultimately becomes negligable, because the deadliness of the enemies is maxed out and you either have really high dice pools even without the armor, or you die in the first hit that actually manages to penetrate the armor/turns you into chunky salsa.
The only players who would try to use these in normal play would be munchkins and well, "Never play with idiots" as they say.