Has anyone tried to install Mcafee's VirusScan ASaP software onto the 715n NAS?

I am looking in installing Watchguard Technologies FireBox X500 onto our network and it comes with a 5 seat subscription of Mcafee VirusScan ASaP.  Hopefully that software will relive me from having to check for virus Updates on computers I do not access every day.

Dose anyone have and opinions on this software or any alternatives to it?

Currently I am managing a vary small network consisting of

1          Dell 715N NAS File Server (Windows Advanced Server LE) (No Domain Controller)

1          Linksys Wireless router (WRT45G)

1          DSL Router

34         Workstations (A mix of Win98 se, Win200 Pro and Win XP Pro)