So I noticed today that GW updated it's 40K Tournament Circuit results. Here's how the different army books stack up as a percentage of first, second, and 3rd place winners:
|Space Marines (all flavors?)||16||29.1%|
|Chaos Space Marines||6||10.9%|
|Black Templars (they're not Marines?)||1||1.8%|
I don't put a whole lot of faith in this being a list of any particular army's "competitiveness", seeing as how very few events really are. But, it's interesting none-the-less.