The CSC (content security and control) module runs anti-virus, and anti-spyware software from Trend Micro.
The AIP (advanced intrusion prevention) module runs the IPS (Intrusion Prevention System) software from Cisco which is the same software that runs on Cisco's IPS Appliance.
The 2 modules protect from different types of attacks.
If you already have an IPS Appliance, then the CSC module may be a better investment.
If you already have anti-virus software on your company's mail server anti, and anti-spyware and anti-virus manditory on all of your company's computers, then an AIP to provide network level intrusion prevention may be a better investment.
The best would be to deploy both, but the ASA only has a single slot.
So if you need both technologies then purchasing one as an ASA module, and the second as a standalone appliance is a good alternative.
