NOD-32 is s-l-o-w...! At least compared to Avira. It takes much less memory than Avira AntiVir or AVG, the on-demand scanner churns through the disks much faster than either of those, so I was really surprised to see how the on-access scanner in the latest version slows down file operations. By default it scans all files, and between pressing F3 (View) in Total Commander on a 70 MB plain text file, and actually seeing the file contents, there was an 8-10 seconds delay. That's nuts! I then changed the confiuguration to scan only selected extensions, but still, it's scanning all the .exes and .dlls and .docs that are going to be slowing down things all the time.
I'm running the trial version of ESS (the suite) right now, and I like a lot about it, but its on-access scanner is really slow, while ESET claim it is very, very fast ("fastest performance", they say). Note that on their AV comparison page (http://www.eset.com/products/compare.php) Avira is conspicuously absent - I guess that's because they only list software that performs worse than theirs.
That is not to promote Avira, necessarily. The reason I'm trying out NOD32 is that I'm looking for another AV product in the first place. I like the look and feel and functionality of NOD32 much better, and the ESS suite is awfully nice, too. Avira makes a security suite as well, but the firewall gave me 3 bluescreens a day, so it was a no-go. (And AVG had me practically reaching for the Acronis partition image on DVD when the uninstaller crashed - I've had a pretty bad experience with it). That's why I'm finding NOD32 even more frustrating - I love it, but the performance hit keeps me from buying. I'll post details of my performance measurements in a separate post.
The only real performance problem I've had with NOD32 over the years have been with anything compressed with UPX or other similar EXE packers. It just chockes on it, and in the case of one of my folders which holds well over 100 different versions of Xyplorer installation files it takes forever+1 to do a scan if I forget to exclude it. Other than that, it has always been great for me.
That said, I still prefer the 2.7 version to the new 3 one. It's not so much the performance, but rather that the cursed exclusion list gets broken and almost completely cleared every time I upgrade to a new release (which is quite often now that it's a brand new program and all...).
In the case of Avira, well I bought a 3 year license a while back intending for it to replace NOD32 as I just wanted to try something new, and after hearing all the praise over and over again over at Wilders I thought I'd check it out. After all, if I didn't like it I could always just pass over the license to another familiy member. Well, that's exactly where it is installed now...and it's not moving back to my own PC anytime soon.
The amount of false positives drove me nuts, the interface when it detects something is a disaster. Why? Well, let me explain. In their infinite wisdom, they made it so that it can't be resized, and because of this it is impossible to read where the file it detect is actually located if it's several folders deep. When you then combine this with all the false positives, you can imagine how frustrating it can get as you sit there trying to decide if you should let it delete the file it just detected as being infected, without having any idea what file it is actually talking about. It should be easy enough to fix, but now almost a year later it still behaves the same way.
Another thing that I thought was really cheap
on their side is that they don't let you scan drives/folders on a network with the regular paid Premium version. Oh no, then you have to give them even more coins
While NOD32 isn't perfect either, it's been a much better experience than Avira ever gave me...