im currently using Norton Security, i know it's a headache , but it's the best solution i found , i found most ANTIVIRUS are pain in neck, if its keep me safe , and mine computer working i am ok with it
I wouldn't touch Norton (consumer version) or McAfee for that matter with a ten feet pole. Bloated, resource hog, too restrictive, trying to protect you from yourself causing you more agony then its worth.
However, I am a huge fan of SEP. I started out with SEP Small business and then switched over to the normal SEP last year, I opted for hosted instead of on-prem. I pay $8 and change per month for two users with five devices each, totaling ten licences total. 'User #1' is my two PCs, my wife's PC and our phones. 'User #2' is used for five of my VMs. I love having the advanced functionality, the ability to customize and the central management. I think Symantec has a great scan engine, but the consumer Norton products are just too bloated. It's nice being able to customize, hence why I will always use business/enterprise products and services over consumer grade whenever possible. Plus you can do some GPO-esqu type lock downs without needing to be on a corporate domain. I use Bitdefender Endpoint at work, while I could use GPOs, I use Bitdefender to disable the USB ports and webcams on certain PCs, I.m sure I could do the same with SEP. At home, my wife's PC has stricter settings then mine, and I always get an email alert if something is detected.
Norton's Antivirus product actually rates as fairly lightweight in the AV-Test tests. 360 is probably a much different story as it is much more involved; pity the fool that doesn't boot their computer pretty much every day as the updates stack up quickly.
I find Sophos Endpoint to be kind of a heavyweight in terms of slowing down the computer. AV-Test rates it slower than Norton in all categories and the impact on infrequently used applications is among the worst (44% slower on "standard" machines -- average is 27%). The protection is as good as most. I find that when the software updates on Windows 7, the computer shuts down without any kind of warning nor does it offer the option of delaying the shutdown.
Symantec Endpoint Cloud rates at or below average on all slow-downs so it is not fair to call it a pig.
Avira is odd as the impact on workstations in a couple of categories is greater than the impact on standard machines.
I've been using AVG Premium + Malwarebytes premium on my < = win 7 computer for a long time now. Seems to work very well and updates happen early AM every day. Now with win 10 I am thinking of using Win Defender+ Malware bytes. Never noticed any slowdown.