Why Should I Buy F-Secure?

I find myself "here and now"  - I run a Linux server - Fedora Core 9 - and have a Win 7 laptop on which I am running Microsoft Security Essentials - which has caught a few viruses and malware so far and doesn't cost me anything (at least for now).

Yet reading up on the "FinFisher" I really get worried about stuff like that and think that maybe I need something more.

I have used various "paid" products in the past, such as Symantec Endpoint, Norton, etc., but find that they either bog down my machine excessively or simply stop support after a few years.

I have read the statement from F-Secure - that they will never bow to governments as far as detection of Trojan eavedropping threats.  I like that very much.

Can F-Secure detect the FinSpy on windows?  Does F-Secure function on a Linux system?

How many have experience here to recommend F-Secure over other possible products?