Apart from its far easier-to-navigate interface, Avast has a few new features that make it hard to turn down. Its new code emulator can emulate a suspicious executable's code, isolated, for use in its new heuristics engine, designed to detect malware that would otherwise be undetectable with normal definitions—in other words, spotting malware by learning what the code does. If you use the pro version, you also get their new sandboxing feature for even further protection.
Apart from the new features, Avast has also lowered scanning times as well as the resources necessary to scan and update—a common issue with antivirus programs that are always running in the background. If you're already an Avast lover (and many of you are), you can either wait for the program to update itself in the near future or go download 5.0 straight from Avast. If you've tried Avast and turned it down before, it may be worth another look—you may find that its former cons (such as the difficult-to-use GUI and resource use) are now more up to your standards.
Avast Antivirus is a free download, Windows only.
