ClamWin is OK for a back-up scanner only, since it doesn't offer full/real time system protection (unless this has been changed with the 0.83 relase)
I see no mention of full/real-time protection being added in the
0.83 release announcement.
There were some other things I personally didn't like about ClamWin. As I recall, it didn't offer the option to clean infected files (only quarantine or delete), and it didn't completely un-install on my test machine.