Yes, that’s what impressed me about it too! 
Thanks everyone all good advice!
I have used Norton for years.
In spite of what some say, it’s always in the top 3 of customer surveys.
(Which, Techradar, etc).
I back it up with the free version of Malwarebytes.
As Judd has said, in a different post, freebies don’t, usually, run all the time.
If a program doesn’t run it’s not doing anything!
You have to remember to fire up a freebie, at regular intervals, and then it will tell you what nasties you caught since last time you ran it! (a lot can happen in a month!)
Not the best way of stopping such as ransomwear, etc.
Defender is always up in the top groups, as well, but the rules about freebies, as said above, will apply to the free versions.
Beware of comparison sites you never before heard of. They may well be just plugging favoured products.
Which & Techradar, in my opinion, tell it as it is.
Thanks Tedc 
It’s reasonable to assume that any PC with a limited amount of Hard Drive, Memory (RAM) , or Processor speed will get a bit (or a lot) faster if you clear out stuff which is using up the resources.
It will, probably, improve in much the same way, if you add a bigger amount of RAM, or Hard Drive, etc.
Keeping a PC perky is about doing both of the above., as time goes by!
I don’t know what resources Windows Defender uses but my computer seemed a bit more nippy when Bitdefender was installed (automatically disables Windows Defender).
However, when I look in Task Manager, Bitdefender is taking up 210-220 megabytes of RAM when sitting idle (can go as high as 400MB if it’s doing something). The computer has 16GB of RAM, so that figure doesn’t matter too much. Quite a chunk for some computers to have running as a background process though.
RAM usage might seem high but Emsisoft (a security program supplier) says a high a RAM figure for AV programs may not be a bad thing. They load their signature databases into RAM so they can give faster protection if needs be. Not sure if all AV programs do this. Maybe the ones with lower RAM usage figures don’t?
Worth noting the article is nearly 5 years old and things change. I think Windows Defender gets better all the time.
My bank gave me Malwarebytes for my online banking.
Sensible, though it’s free of course. I have it too.
10 or 15 years ago my bank, HSBC, asked me to install av software Trusteer Rapport, which I did. They don’t mention it or make any recommendations nowadays.
It is the premium version of Malwarebytes JBR free until at least June 2022. I have already had it for two years.
Funny you should say that d00d. My bank who have given me Malwarebytes Premium used to use Trusteer Rapport but I had to get rid of it as making my laptop very slow.
Is it?
Oh, mine is just the common or garden variety!
So does that mean I can just download the premium version until June 2022?
No, it is only for customers of the RBS. I would imagine that NatWest would have the same offer.
Ah! Perhaps I might mention it to First Direct. 
Actually, I said that the free versions don’t automatically update their virus definitions.
I bought two lifetime licences for Malwarebytes in 2011. There have been long periods of time (years) when it hasn’t been installed.
The last time it was installed for a while was about 3 years ago. Even though Malwarebytes had undergone a number of version upgrades, the licences were still active …as promised.
It’s not installed now but if I go into my Malwarebytes account, those lifetime licences are still active. I can download and install the latest full version if I want to. True lifetime licences.
My bank offered Trusteer then stopped because they use the OTP approach (they send me a text with a code to enter before I can access my account). For some reason, they’ve started offering it again which is damned irritating to say the least.
I use Bitdefender Pro for my anti-virus/firewall and Malwarebytes Premium - none of these slow my machine down and are very efficient. MB for example can detect whether a web-page has been hi-jacked with a trojan and won’t allow me to go any further.
My bank is offering it too.
Sorry about the mis-quote, Judd!
No problem. 