You can't really say avant is light on resources as it isn't a browser but a wrapper that goes round IE's infrastructure. So you would have to somehow include the IE resources also being used to truly determine resource use.
It also inherits the vulnerabilities associated with the version of IE that you have, although it is a little easier to flip flop the security settings for activeX, etc. so marginally more secure. It is my browser of choice if a site absolutely requires IE to be viewed correctly, etc.
However with the firefox add-on, IE Tab that is also lessened.
