This is the kind of thing which shouldn't be going to court.
Although blogging is often seen as a relatively faceless pastime, everything that is written passes through a search engine filter at some point. A good rant can often be ranked highly for firms with unusual names that don't have good presence online.
For brands and companies with names and reputations to uphold there is an overwhelming temptation to take legal action. However this can be regarded as short sighted - although they are extremely likely to win; it could be a pyrrhic victory. The impression given by legal victories is that the big nasty company came and beat up the nice independent guy.
Far better (as long as the opinion is actually wrong) to engage the wronged party in robust debate. Yes there could be a bit of an argument but it should be seen as an opportunity to discuss particular aspects of a company. It is usually better to show that brands listen to customers rather than slapping them down.