Does anyone have any suggestions for someone who (like me) is really bothered by this? Does anyone know if someone has done a rewrite of the classes to balance them across 20/36 levels?
The point of the "old school" balance wasn't all about equal level = equal power. There was quite a bit that came from play style or alternate balancing.
My group never saw wizards as being particularly overpowered. Most power came from the end of a sword or from being a smart thief. On the other hand, I never found 1st level AD&D wizards to be underpowered because they often stayed close to town and prepared spells based on known tasks.
Old school wasn't supposed to keep all characters balanced in all situations -- including combat. Combat was just one more area where a character may or may not excel. Really, it was about finding where your choice of class and concept
did excel and running with it. A thief would never consider going into "fair" melee combat because that was absurd. But, the right thought process could result in an insanely effective thief soloing against an entire cult.
As much as I like 4e, this is one area where I have concerns (and disliked 3e). I don't necessarily
want all character classes to be equally effective in combat situations. I want rogues to shine more than others when stealth and subtlety is important, fighters to shine when it's a straight-up battlefield, and wizards when there is some fantastic problem or knowledge-based task.
Having said that, I just played a 3e wizard with a full battery of knowledge skills. It lasted one adventure. It was incredibly cool to be able to bring my full player knowledge to bear, including being able to rattle off all the monster weaknesses and identifying magic items from memory. After a couple of sessions, though, I'd given all my knowledge on the situation and settled into the resource management role. Even at 6th level, with a 22 int, I didn't feel like I had enough spells to actually last the day (and I
refuse to be the source of the 15 minute adventuring day).
What I really want is a happy medium where different classes unquestionably shine at different times and in different ways, but no one is ever completely useless.