Nice plugin. But one drawback in the version for joomla 1.5. When the tag contains to many characters it does not give you any result.

When you read their forum you'll see that the speed of support is slow slow slow, which does not come in handy as this product gives a lot of problems to set up.

Read their refund policy very carefully

http://www.joomla-tags.com/kb/refund_policy/

as you most likely will be interested in, after waiting for any respond while having all sorts of problems.
Also, the statement about not giving 3rd party component integration compatibility and support, has not been stated by the developer with little reason.

I think the product when eventually implemented can be great, but the complete product, so speed of support included, is poor (I am amazed to see that other reviews tell the opposite?!)

Don't buy this product if you are in a hurry and don't like the risk of having implementation problems!

While normal SEF and opensef did not work on my site, JoomSEF did immediately.