Ordinarily, I would attempt to make a pithy observation regarding the irony of conducting a discussion about the pros and cons of the internet on an online forum, and perhaps point out that this may lead to a slight skewing of the outcome. But, this being the CR, an exception can be made.
And now for some serious points. Don’t have it in your house. Not with a filter, not with a password, nothing. If your child needs it for school work (and only for school, I can think of no other justifiable reason), then they can do it elsewhere in a supervised environment. This does not stem from over zealousness, but from a more liberal attitude. Having something like the internet in your house, even if you only take it’s addictive nature into account, is removing the child’s free will. When they’re old enough to make their own mind up, step away, but as regards bringing up children there is no real other option.
And if your child is anything like any 8-12 year old of today, they know more about computers than you do, and any filter can be circumvented laughably easily. This includes every filter TAG offer, including K9 and ConvenantEyes. Just don’t take that risk.
Personally, I was bought up without internet in the house, for which I am constantly thankful. I look at some children today who have access, even very limited, and it is completely ruining them. So, to paraphrase Nike, just don’t do it.