If you can load Windows then you can use cloud based scanner.
You gave one reason to use traditional virus scanner instead of cloud based and i gave the solution for it. So Nothing wrong with that.
And I gave the flexible solution without saying only use cloud scanner. You can use traditional anti virus boot disc if you already have lot of viruses inside your system and can't boot.
But its not a reason to run traditional scanner leaving behind all the advantages of cloud. Using traditional scanner mean you are less updated and there is a big risk in every passing second. You waste system resources unnecessarily. So use more power but slow down your work.
wrong.
Being able to load windows doesnt mean the AV (cloud or otherwise) can be loaded. I'm sure eve you have had experiences with viruses that specifically blocks AV guards from running or getting updates.
A virus that hijacks the hosts file or the dns cache and blocks the Panda's server cloud will effectively kill the usefulness of the the cloud AV as it is no longer able to get the updates and as its having no local AV database, it cant perform a local scan as it doest have the updated signatures to detect the virus.
At this point, windows is loading, the cloud AV is loading but the virus is running and taking over the PC.
On high resources systems, the resources taken by AV is not noticeable at all. On low resources systems, the cloud AV will perform better.
Like I said before, Cloud AV is useful only for certain situations. Not all situations as you seem to imply.