Hello AdamPaterson and A55A551N-11B3P,
I'm Using a Microsoft Wireless Comfort Desktop 5000 series, both for my Windows 8 and Windows 7 machines, with IE10, and I have a delay that varies from 1 to 3 seconds, depending the web page that should be loaded.
First, you should take into consideration that IE10 has been designed and optimized for Windows 8, later, Microsoft has made available IE10 for Windows 7 and in this OS the browser is slightly less powerful than on Windows 8.
The proof of this, also lies in the fact that several users who had updated their browser to IE10 on Windows 7, they then did the downgrade to the previous version.
I personally continue to use IE10 also on my Windows 7 PC, whereas the decline in the performance I still acceptable. Of course, you may experience different results on other computers having different hardware and software configurations.
I agree with what intesec explained on the first page, message #2 of this topic.
Also, there are web pages that are very heavy, with so many and too many plug-ins such as Java, Flash Player, MS Silverlight, etc..) that have a relevant influence in the loading of these pages.
At the end, considering the complete package of protection that NIS provides for the web (in addition to the Norton Toolbar), which must scan the contents of a page before we get access to the same, the delay of a few seconds it seems to me more than acceptable, this also means that NIS is protecting you adequately.
Sandro