'live environment' means Production Environment - like servers, etc. atleast in some business usage - for big organisations. Sorry I work as a techie for some of them.
McAfee is certified for such use and I assure you, AVG will piss of before their certification procedures. I won't elaborate because of obvious reasons.
Several times I have seen AVG kneeing down, though I used to prefer AVG since its free.
Norton is a system hog and have used KAV for sometime......dont know about much about Nod32. I have been using AVG for over a year now and liked it as its very light and doesnt hog up the system as Norton...At my university they use McAfee everywhere onall servers and and McAfee has firewall and other stuff which AVG doesnt have and never really liked the AVG firewall and I get McAfee for free from my university ..Thats why the question...Maybe I will stick to AVG..