You will love ICS. Takes less time to set up then taking a crap. All you have to do is go into your nic properties that your ineternet is on and click internet sharing. It configures your other nic that is on your network for you. Then just set your other comptuers to use dynamic ips and you are set. Took less then 5 mins to configure. Oh ya, you will want to delete all your old configs in your internet programs that you had from the proxy server. This works much better then a proxy server too, ICS is 100% transparent. Im sure you know how frustrating a non transparent proxy can be. You asked for the bad of ICS, well cant think of too many things. For one you cant use static ips, which I like, but cant use. You can use them, but microsoft dose not support if it will work or not, it didnt happen to for me. The disadvantage may be that you do not have internet site/adctivity logging or restriction, or a built in firewall. You can download other programs for logging internet activity, and you can get a firewall like zonealarm which is free. Here is a question though for anyone who knows more on this. ICS did not work for me until I used the same subnet on my nic that has my cable modem on my nic that goes to my network. Anyone have any ideas on this? Weirdest problem I have ever ran accross.
Hope this helps
Garrett.