The resource usage could be a little bit more netbook friendly (especially during on-demand scanning), IMO. Boot-up and shutdown time could be improved as well.
I dislike how the virus alert notifications popup in front of my screen, its a bit intrusive (though AVG is much worse).
I heavily agree with this one, I can notice a noticeable performance impact when doing scans in my 1 Ghz 1GB RAM Test PC. GUI improvements are also welcome as long as its not too flashy and buggy too.
When scanning it does access the hd a lot and can slow down things. May be Comodo can add priority settings for the av scanner.