This extension has so many features, it is well documented and it managed to build our site's sitemap for seconds although we have around 3000 links. What is best is the support, I've had an issue which was related to Firefox I contacted John and he was emailing me half a day, in the end we skyped, he didn't leave me until the problem was resolved. I wish all the extension's supports were like this. Thank you John. It's worth every cent.