I have worked in internet sales in the past, and we had an online review system. You can not have just an open review board, and it go live automatically. If you do, its the worst idea, and asking for trouble.
We would get reviews that didn't make any sense to the product they were reviewing, let alone, they didn't buy it from us. Ours actually showed the IP address to us. You would have some that posted horrible reviews, and if we knew who it was, we would reach out and try and make it right. A lot of time our products, it came down to user error, though not all the time. Not that I think you should only post the 4 or 5 star reviews, and leave out things that are fitting to the product. We at least always looked at the reviews, and then would talk about them every couple of weeks, and if we needed to change something we would.
Keeping that in mind, if I have an issue, and can't get an answer from the company, I would post it to the review site, since I know someone has to see it. Very few companies allow it to post immediately. Shopping sites like Amazon, are some of the fastest to post though, since they can have a team dedicated to anything related in that area. And reviews can make or break a product there. And all companies know about the forums, just like this one, and are most likely either sponsers, or signed up to get notifications when their name is included in a post. You have to be proactive, and know when things are being talked about. Even if it is some kid, mad at your site at 3 in the morning.