I haven't used IE7 enough to express a personal opinion on it. That's why I wrote '
and is said to have better overall security' rather than '
it has better overall security'. If you read about
IE7's security then it does look to be a better browser in this respect. However, you're right. No matter what the features are, there can always be flaws.
This isn't the case with only IE7. It seems no matter what the browser, there are always vulnerabilities that arise from time to time. A bug on Firefox's Password Manager has recently been written about for instance.
I do think it's the case that some of these flaws (no matter what the browser) can be difficult to fall foul of in everyday browsing. It usually takes a certain set of circumstances for them to have any effect. Although flaws have been numerous in Firefox, I can't say I've ever suffered because of them. I've never done, in everyday usage, exactly what is necessary for a flaw to harm me or my computer. Could this also be the case with Internet Explorer 6 or 7?