Well, speaking seriously on the topic at hand ...
'Game balance' in Shadowrun is not IMO something that needs to be performed between players. A security platoon that is a threat to the made-for-firearm-combat street samurai should wipe the floor with the close-combat adept, the spirit-caller shaman, the hacker, or the face. Why? Because they're not made for that. In the same light, a street samurai gun-bunny should not be hacking, calling up spirits, negotiating, or go toe-to-toe - and expect to regularly beat the others, i.e. more than one time in four or five. Why not? Because those are their areas of expertise.
Shadowrunners are meant to have the areas in which they shine. In those areas, they should be two steps ahead of anyone but the guy who is the dedicated second-placer - and if you look at the game design for starting characters, that's actually part of the idea. What's the cap on skills? One 6, any others at 4 - or else two 5s, and anything else at 4. The best gunslinger that deckerman is suppsed to be is two steps behind gunbunny - and the best hacker that gunbunny is supposed to be is two steps behind deckerman.
"Balance" in Shadowrun is meant to be between the team and the opposition - and as a consequence, it's something that the GM needs to take care with. Yes, the security platoon might catch the non-gunbunny PCs in a withering crossfire that wipes them out (or so they think!) because the gunbunny wasn't there; that's always a possibility. The other PCs can influence that, whether from information, or clever use of a spirit, or even just getting the chance to pretend they're good corporate citizens and fast-talking the guards to let them by, they're running away from the crazy dangerous shadowrunners. Perhaps the Kickass-Fu adept manages to get into position and turn the threat range around, and has his own defining moment of cool.
But even if the troll drake adept is great for tearing apart Citymasters and setting someone up to pose a threat to his massive abilities endangers the rest of the team, it's the GM's job to make that threat-to-the-rest-of-the-team one that overwhelms them but doesn't kill them. Or leans it so that the team's entire plan is for the TDA to take his licks and get his ass kicked in order to distract The Threat while the rest of the team gets the job done. That is what game-balance is.
Yes, it's all in the hands of the GM. And yes, there will be times where you want to threaten the other PCs with stuff in areas they don't have - but that's where forcing the group to split comes in, and bringing in a danger not-quite-as-great as The Threat. And yes, there will be times when the GM REALLY doesn't want to have to bring in a juggernaut or a dragon or a panzer or an ATGM or disable the possibility of the TDA shapeshifting into his car-killer form into the game.
Game Balance between players is, really, a gauge of the difficulty they each face in their speciality. I agree completely if the GM doesn't want to have that power level in the game, and for that reason I wouldn't expect the hacker to be dealing with Geneva Orbital, or the face staring down Richard Villiers. If the face isn't there, then the players are going to get wiped away by Villiers just as thoroughly as if the gun-bunny wasn't there and they were facing down the Ultra Team of the corporate security. Balance your game there - not in whether or not Juju the spirit-caller is going to be able to win the same combat that 5.56mm the street sam is.
