The "informed consent" popup window method is very intrusive.
It's worth noting that the majority of major UK websites (eg. BBC, Guardian, Telegraph) that have so far implemented the cookie notice have opted for the "implied consent" method, which is far less intrusive than the "informed consent" method which typically involves a popup box like your plugin provides.
I'm unclear whether the "implied consent" method strictly complies with the law, but it certainly complies with the ICO's recommendations, and if major news organisations such as the BBC are doing it then you can be pretty sure that you're safe doing it too.
To that end, it would be nice if this plugin provided the option to display a top banner on the site with the implied consent message instead of the popup box. I'd hate to start seeing too many of these popups appearing while i'm browsing the web.