I can answer this question with some logic.
1. Most Comodo users are fanboys who have plenty of time to configure and tweak settings which make most bugs unnoticed.
2. Most Comodo users are active in their forums and have a lot of time to read guides and help documents.
3. Most Comodo users know that bugs do exists but try to cover up the facts to defend Comodo's honor.
All software has bugs where users want to accept the facts or not.
There is not such a thing as a software with zero bugs.
It all comes down to how users can deal with the bugs, if a user knows how to get around them then they might say this software runs perfect, if they don't know how to get around the bugs then they will say this software is buggy.
Fanboys of any software will know how to effectively get around most bugs therefore will try to pretend that no bugs exists.
However getting around bugs sometimes takes a lot of work and time and most users don't want to do this.
They would rather have a software that is maintenance free and doesn't have to be tweaked.
So is Comodo really buggy??
YES and NO- it depends on your user experience with the product.
For myself, from past experiences with Comodo and don't think it is worth the problems no matter how good of protection it can provide. I simple hate it when a security product blocks safe processes or detects false alerts and I don't like having to keep tweaking and configuring a product to allow these safe processes.
UAC runs at Windows kernel level with can block all software based malicious processes, Comodo only runs at the software level below the kernel level which can not protect against Windows OS vulnerabilities. Any malicious process has to go through UAC before it reaches Comodo. So UAC offers much better protection if utilized therefore there is no need for me to use another security software with advanced protection features. A basic AV is all that is required.
So if you like Comodo and don't see any bugs in it then use it, if you have experienced bugs that you can't deal with then use another product. No reason to fight about a product that none of us owns or even knows the developers personally who design it.
Enjoy!!