Ultimately, if you’re running Chrome anyway, it’s a moot point. If you primarily use Chrome, just keep using it and keep it up-to-date (which Google does transparently for you).
I’d probably have you update Internet Explorer, but not for the reasons most people think.
Which browser should I use?
I tend to agree that your six-month waiting period is probably a good one. Internet Explorer 10 is past that now, so it’s probably okay to install. I’ve not heard anything negative about it, above the usual grumbling that happens with every new release. I have IE 10 installed and use it from time to time to test various things, usually in response to reader questions.
Like you, I run Chrome most of the time. I happen to be more comfortable in Chrome, but honestly, at this point, it’s splitting hairs. The three major browsers – IE, Chrome, Firefox – are all good.
Keeping IE 10 up-to-date… even if you don’t use it
Even if you use another browser, it is in fact a good thing to keep Internet Explorer up-to-date. That means making sure you’re taking updates to Internet Explorer as they come from Windows Update. I don’t’ necessarily mean version upgrades, but the patches for IE 9 that you are already (hopefully) getting.
At some point, upgrading to IE 10 is a fine thing to do, and probably something you’ll want to do. There’s no rush, today, but eventually you’ll want to make the move. It keeps you current and makes sure that you get the latest patches. At some point, IE 9 is no longer going to be supported (much like IE 6 isn’t today).
I would strongly recommend that you continue to use Chrome the way you’re using it. Upgrade to IE 10 whenever you feel like doing it. Like I said, as you’re using Chrome, I don’t see a huge upside other than preparing for the future.