Yes, after reading on the forums about some problems various users had after upgrade to 3.10...530 I decided to stay put and wait a bit before accepting CIS's automatic prompt to upgrade (from 3.9). Yesterday, after seeing nothing but good news about 3.10...531 I wanted to give it a go, with a fresh install. Went to the main website to download it and ... could not find anything that looked like free CIS download button anywhere. I found the "Free products ..." page http://www.comodo.com/home/free/free-protection.php
with Antivirus, Firewall, AntiMalware etc, all mentioning they are now also part of CIS. But no CIS link, other that the CIS Pro trial.
In the end I had to abandon my plan of a fresh re-install, cause I found no way of actually obtaining it from the website. Eventually I accepted 3.9's prompt to do the upgrade for me (worked seamlessly, BTW).
So, yes, I would really love to recommend CIS to my friends, but I'm unable to just say "go to COMODO website, you'll find it all there" at the moment.
BTW, I had no such problems 3 weeks ago installing 3.9 for the first time ... very impressive piece of software