Let me clear something up - I'm not a computer expert. I'm a man of simple means, and when I download 'Avast', I use the link that pops up on 'google'. Also, when I get a pop-up from Avast telling me they've got an 'update' they think I should download, I trust them and do what they say.
To me, a 'beta' version of anything is like buying a prototype car, it may look good, but the customer is expected to fix/report all the faults so the 'proper' version can eventually be released to the general public. I consider myself to be firmly a member of the general public, and therefore expect that when Avast ask me to 'update', it's to a version that has been tested & works...
I know there are many folk who find it a hobby to download 'beta' versions, discuss the endless pros & cons on internet forums, suggest fixes to the developers, may even write a bit of code on the side to submit - but I'm not that guy.