Another thing I didn't really think about: "equal-weighting means selling winners and buying losers each quarter to maintain balance. "

Well, the evidence shows that it's better interpreted (statistically) as "equal-weighting means selling overvalued stuff and buying undervalued stuff each quarter to maintain balance. " Yes, the trimming sometimes starts before the overvaluation level, but reliably skipping big allocations to overvalued stuff is a very big win.

You're right, equal weighting does require more trading than cap weight. But so what? You're still better off. Higher average returns even after fees, vastly lower company specific risk.

Cap weight, it should be noted, was originally invented as a way to track the market's general level, NOT as an investment strategy, which is just as well. Fund management companies really appreciate the lower trading, but I don't see it as a plus for investors.

If you have a credible reason to overweight something, by all means overweight it. But "it's a really big company" doesn't really make the cut as a credible reason : )
You're looking for the most total return per dollar you invest, not the most total return at head office.

Jim