I had McAfee many years ago - it came with 1 year free when we bought the computer so we kept going. When we wanted to cancel it became a huge pita. We knew it was due for renewal in October, so we sent an email in August stating we wanted to cancel. By September mcAfee said "we want to make sure your comp is protected, so we'll renew your subscription" ie early. Three emails later and no reply we got a message saying "Please tell our marketing consultant what your experience is of McAfee in the survey attached". So I let rip, stating If they didn't cancel and give a refund I'd be contacting the UK Press and Consumer associations. A week later we received a refund (and still lost £2 due to currency movements but hey-ho I was just glad to be without them. The only time (that we know of course) we had a virus McAfee didn't alert us, isolate it, or get rid of it - It took us 45 mins with a set of instructions from a friend. A very clever virus, it had used the mailbox of someone in our car club and sent us all the virus in an email for a subject he had used and we all expected the mail that came from 'him'
The thing we did wrong when signing up to McAfee (this may benefit other people to know, and applies to any subscription) was to agree to a continuing payment (sorry I don't recall the name) which wasn't a direct debit or standing order so we couldn't stop it via our bank!
ETA The virus we got was particularly clever because it downloaded because the preview page was active, and didn't need a file downloaded (indeed I definitely didn't download anything because I saw the file attached was .exe. Very clever scammers/destructive people out there!