F-Secure IS tested at AV-test.org, April
F-Secure does very well as usual; http://www.av-test.org/en/home/?avtest%5Btype%5D=3&avtest%5Bplatforms%5D=10-7&avtest%5Bseries%5D=10-7:1396310400.2
"evaluated 25 home user security products using their default settings" on Win 8.1 (64-bit).
I see Avira did as well as Bitdrfender. That's good for them. Kaspersky seems to come top with most things, but I've always found that it slows web browsing down. I wonder why that never seems to be mentioned? It's one of the reasons I came back to F-Secure from it.
Avira has improved dramatically in the last 6-7 months with its Protection Cloud feature. McAfee and Panda have also shown big improvements of late. But as long as you do not consider an AV as your ONLY anti-malware, then most of the AVs listed can be run in a layered defense. (okay I would think twice when choosing Ahn Lab or Windows Defender ).
I am running KIS on two machines as I receive free licenses from my Bank. KIS 2015 RC running as light as a feather here but I know some users have reported slowdowns.
I am running it with AppGuard and only have the KIS file and web scanners enabled; both systems are very fast with this setup with no slowdowns whatsoever. Now if Barclays offered F-Secure!
Well, perhaps F-Secure could make them an offer, like with Virgin! Might keep us busy for a while again.
As for KIS, I don't really have the facilities to try it again at the moment, as I've got FS on both machines. My last expedition into KIS world was in 2011/12, when I still had Windows XP. It certainly made web browsing slower, with the web scanner enabled. I guess it also depends on how fast your internet connection is, and if you have Fibre, for example, the difference may not be noticeable.