I am known to have tried many AV's and liked something about each one. Recently I had Avast 4.8 installed and it ran very well. And before that I had AVG 8.0 which didn't. I now have the AVG 7.5 Pro installed again, that I've used off and on for a long time. And I have to say it runs lighter than any AV I've used including Avira, which is my second favorite. Also it always ran well with any other security program I used. I think Avast 5.0 will be awesome. Avira 8.0 will be even better than 7. And AVG 8.0 will improve. But for now it's a pleasure using AVG 7.5 for the reasons I mentioned, plus it's not too shabby on detection. Say what you will about the interface, or that some other AV's have better detection. But I for one am going to miss AVG 7.5.