Hey all,
Not to be a jerk, but I'm not real keen on reading 10 pages to get in the mix here, so I'll be concise and preface this with a blanket apology if I mention something that's been said already.
In the long term, I think the orb spells are arguably balanced based on their inability to deal damage to more than one target. A fireball catches what (?) 52 squares in a tablegrid? If there's a viable target in each square, the fireball puts out 520d6 (avg. 1820 points, maxed 3120 points) in one shot. Sure, it's distributed and divided evenly to each square, but that's part of the point, isn't it? A fireball can deal oodles of damage across the board where an orb can guarantee a sizable amount of damage to one target.
Things you have to concede on the issue, and I mean everyone:
1) No SR means affecting golems and not having to worry about high-SR foes; this is good but not a deal-breaker. There are (a few) high-end baddies with no considerable magic resistance.
2) Touch attack doesn't set this spell apart from most others. Polar ray is a touch attack, ED is a touch attack... what's the big deal? These spells ignoring physical armor is almost a given, to me at least, given the fact that I can't really think of any other way to do it. If the orb of fire touches you, you burn. End of argument.
3) Having a higher damage cap (all 'cept orb of force, since force damage is so hard to resist) is part-and-parcel for being a level higher. The fact that there's no SR is 'balanced' against lower level evocations by the single-target restriction
4) There are so many rules and spells and conditions out there that people can keep pulling out of the hat that there's no way to conclusively prove whether the orbs are 'broken' or not.
5) The additional effects of the spells is, IMO, what pushes the envelope on their design. Orb of electricity is fine enough, adding a blinding (or whatever) ability to it is edging on too much icing on the cake.
6) Twin and Admix are frickin' terrible metamagic feats and should be stricken from the record, saving us all a lot of needless back-and-forth on how jacked-up a spell can be made, thus proving or disproving someone's opinion on the issue of balance. I know that we can't very well ignore these feats, but they need to be taken with a grain of salt, since all these feats serve is to lead to these kinds of issues: namely that once you start slapping Admix and Twin onto spells, especially like the orbs, you start to grit your teeth. Going for the orb spells might seem intuitive, but it's more the fault of these feats than the spell itself. Stand alone, empowered or maximized or both, the orb spells are worth the price of copying to the spellbook, but throw in these metamagics and you wake up a whole can of worms.