Competing Microcap ETFs look good

It seems that Ishares and Powershares have just came out with two competing micro-cap ETFs. One follows an index (IWC) while the other is actively managed to pick the best micro-caps out there (PZI) They seem like an interesting tool to diversify your portfolio.

I like the idea of the actively managed one myself because they pick out the stocks that look like they are going to make a decent return. A good manager can do very well by picking the right micro-caps to invest in. I don't like how they are benchmarking against some Zacks proprietary index though. It makes it so it is too easy to move the bar on the shareholders.