Back in the day, I was die-hard Norton AnitVirus. If it was anything other than Norton, it was crap. My Dad was a die-hard McAfee user and swore by it. So, about 6 years ago, I switched to McAfee AntiVirus and have been a happy (and loyal) customer ever since. It didn't popup unimportant messages to me and I liked that. It just worked. A few times, I found it helpful when things would go wrong and I was able to track down certain activities of "suspicious" behavior over my network that made their way into my computer. I can't remember exact instances, but I do recall feeling fortunate to have the utilities that McAfee offered me when I got paranoid about other people hacking into my machine.
Recently, I've been spending most of my time OS X. There just aren't as many vulnerabilities that I can see with the Mac. Maybe I'm being naive in thinking this, but I feel more safe on my Mac. (?) Almost all of my daily use and personal computing has been done on my Mac in the last 2 years. I'm even trying to transform my dev skills to be more Unix-savvy so that I can (one day) rival my own Windows development skills. :) I live in OS X, and only use Microsoft Windows for work now. In order to use Windows, I have a separate partition setup and then I load the OS through BootCamp into my Parallels 6.0 application. It works great, and I'm even using a UI skin called "MacLook" to make my Windows dialogs look and feel like Mac dialogs. The problem with this configuration is that I have to allocate a certain amount of RAM to my VM. It can't just take all of my RAM and divy it up between my Mac OS. If it were up to me, I'd drop Windows and become a Mono head, but I can't; my job requires that I work with Microsoft .NET Framework. Therefore, I am forced to have Windows installed as a Virtual Machine. It pays the bills, and... well let's face it: Businesses run on Windows. In order for me to provide "business solutions" to "businesses", I need to develop applications on Windows. Period.
The other day, my Windows VM came to a screeching halt and I wasn't able to do anything on it without inferring a 15 second delay of every action. This went on for about 3 hours or more. Amazingly, my OS X environment was working great and was still very responsive. I was only running Visual Studio 2010, Total Commander, and FireFox (to debug my ASP.NET project). I had just installed a new tool to allow me to interface with Microsoft Office from inside my C# projects, and after doing that, my machine became incoherent. I checked and made sure that McAfee wasn't running a full virus scan, and it wasn't. I couldn't make sense of it!!
Eventually, Bob and I had to do a GoToMeeting and I had to give him control of my Visual Studio environment. How embarrassing!! My machine was behaving like a 1990's Tandy T1000, and he had to wait for simple operations like I had been doing for the last 3 hours. He and I decided to find the problem... Low and behold, it was McAfee's "Real Time Scan" feature. Since I'd downloaded all these new tools, Real Time Scan was going through and making sure there were no viruses on them. Not sure why it took so damn long and required so many resources, but it did. I decided to turn off the Real Time Scan feature, but as soon as I did, I began getting all kinds of red prompts stating that MY COMPUTER IS AT RISK! WARNING! WARNING! WARNING!... Is that really necessary? C'mon! I've been putting up with all of the slowness from this thing, and now when I try to turn it off, it annoys me even more with false panic prompts.
Once I disabled the Real Time Scan, my VM started to respond better. After voicing my frustrations to Bob about this happening more and more lately, he pointed me to a free alternative called Microsoft Security Essentials. It's free and it doesn't hog up resources like McAfee does. Yesterday, I took the plunge. I uninstalled McAfee (only 1 month left on my subscription anyway), and installed Microsoft Security Essentials. So far, no big red prompts and I've not had the "bog down" problem yet.