a question for those using the beta

How is the anti virus in 4.0 compared to 3.14?

At this stage, very similar. The updating of the virus definitions is better, mainly due to the updating status being more detailed, so you know if and what is being downloaded, then installed.

The merging of updates into the AV database is slow, but it may be related to my system (although other apps run OK on it).

Speed of scanning is very much the same.

How about the detection? Is it better in 4.0?

[b]Changes in Antivirus[/b]

1 - AV Updates
Unlike the previous versions, AV now reports the download status in a more granular way.
2 - Various improvements in the engine for better detection: i.e. better emulation, more unpacking etc.
3 - Improved cleaning support
The new engine introduces Disinfection support for the infected files in addition to deletion and quarantining. Also CIS4 now includes significantly improved file deletion, quaratining support to get rid of persistent files.
4 - Scanning in Safe Mode
cavsan.exe is designed in such a way that it can be used to scan for viruses in windows Safe mode or it can be used by various 3rd party applications through the commandline.
Doubleclicking on it will also allow the users to do virus scanning.