I'm not sure since I never tried Sophos, Kaspersky, Eset NOD32, VIPRE Antivirus, or Trend Micro.
Free anti-virus usually have less support in my experience since I notice the only support is the forums on AVG, Avast, and other freeware sites, but paid antivirus like VIPRE has a live support chat, technical support phone number, e-mail, and their support forum.
Re: Is free antivirus as reliable as the "Best" paid antivir
I don't see why not, when you find $50 dollars on the ground it is free (in the sense that you found it) and it is valuable because it is money nonetheless.
Re: Is free antivirus as reliable as the "Best" paid antivir
I don't think "reliable" always correlates with "best". Best is merely a personal choice, whereas reliability is independently tested according to a set criteria, though they both have similarities.
There are many reliable free Anti Virus software that do the job, just like paid Anti Virus solutions (eg. Avast!, AVG, Microsoft Security Essentials). To be fair, if the name has been heard before, chances are they are good enough to use without paranoia that your computer is going to be harmed.
Re: Is free antivirus as reliable as the "Best" paid antivir
If you mean reliable as in they work; then yes they are about as reliable as each other. If you mean reliable as in detection rate then I would disagree as many free anti-viruses use virus databases from user submitted and anti virus analysis; with that in mind paid anti viruses use resources from each other's databases as well as user submitted ones and from websites such as www.novirusthanks.org which they pay for the information as well as paying analysis teams and such.
There is also a possibility of the coding being a great deal better with paid which could mean a faster scan and detection.
This cannot be a full assumption as free Vs paid is like stating red or blue but the ideas are there.