IE9 is up to 68 on the ACID3 test.
Internet Explorer itself is finally starting to lose market share. I’m a Chrome user; I ditch browsers as they bloat—rendering is usually a secondary concern for me (if there’s a site that demands one particular browser, I use that browser for that site only). There was a time when IE was less bloated than Netscape; a time when Firefox was less bloated than IE; a time when Chrome was less bloated than Firefox; and a time when Safari was less bloated than Firefox. Right now Chrome is the least bloated, at least in my uses.
IE9 could recapture a lot market share by simply taking advantage of its default status on Windows better. Less bloat, more standards and people wouldn’t ever bother installing Chrome or Firefox. Though I’m not really sure who cares to win the browser wars if they all are based on open standards and are free.
No matter which browser you use, though, I think you will find your experience drastically improved by a Flash blocker.