How should an optimal review look like? Ideally the reviewers should answer:

(1) First and foremost, in my opinion, does it work as promised?
For example I just downloaded and configured AnalyticsForPlone
which I heard was a great Product, but I'm having trouble getting
it to work with Google Analytics (it installs fine and has a
reasonable UI) so now I'm wondering: Is it me? Is it Google Analytics?
Is it the Product? It would be great if there was a rating or
something that would tell me it's not the Product's fault
(through the testimony/evaluation of others). Most likely
it's not in this case ;-)

(2) Second (for me): Is this product the best at what it does?
Are their other Products in the same category that do it better?
Are their particular features of this Product
that are better/worse/missing than in other similar Products?

(3) Third: Is this Product easy to install or are there a lot of
dependencies required to make it work? Sometimes having
the Product distributed in a bundle with it's dependencies
can be the difference between you trying it and not trying it.
Ease of install, along with the other ratings can
help you evaluate more completely and save you time/money.

(4) Fourth (and less important to me but maybe very important
to others) is User Interface. There is nothing like a
great Product with a great UI that works great! But a lot
of Products are in development and function well but
have a horrible/kludgy UI that leaves you feeling
dirty after you use it. What I'm really curious about when
trying a new Product is what bells/whistles is this going
to give me? Does it have a QuickInstaller? Do I have to
use the ZMI to configure it? A great UI is not a requirement
but certainly makes the experience of using the Product
much nicer. Perhaps a rating that indicates that Limi
himself has looked at and approved the UI for this
Product would be useful. In other words, does this
Product fit with Plone in the way something added to the
Plone Core would?

In short:

1. Does it work as promised?
2. How does it compare to other Products?
3. Is it easy to install?
4. How is the UI?