I noticed that our Adobe CS6 installations (using an AAMEE package) were surprisingly slow (as in five hours on a fast machine). I've worked out the cause of the problem, and am posting it here in the hope that it will help someone else experiencing the same issue - also, if anyone from Adobe is reading this, it would be nice to get it fixed, at least for future releases. :-)
The problem is that our machines don't have direct access to web sites on the internet, i.e., port 80 traffic is blocked by the external firewall. I discovered that the CS6 installer was repeatedly attempting to contact various web sites, including crl.verisign.net, presumably in order to validate digital certificates on files in the install package. Each such attempt had to time out before the next was made. Configuring Windows Firewall to block these attempts reduced the install time from five hours to thirty minutes.
On Windows 7, this command can be used to install a firewall rule that will block outgoing port 80 traffic:
netsh advfirewall firewall add rule name="block www" dir=out action=block protocol=tcp remoteport=80
Once installation is finished, this command will remove the rule:
netsh advfirewall firewall delete rule name="block www"
For later versions (Adobe CC and onwards) you need to block port 443 as well as port 80.