Great quality extension, much better than other sitemap extensions I have tried. Interace is very clean and has a lot of power. Customer service is excellent, after having 1 issue(not JSitemaps fault) they helped me fix it very quickly.
My experience with Cobalt 7 and it's dev team has been great. I am using this tool to create a staff directory for a university where faculty can be linked to classrooms, labs and departments using the relational field in Cobalt. I recommend buying the complete package to get all of Cobalt's features. Support has been top notch.
Using this on a 1.5x site. Works great and looks very clean. A big plus for me is how well it combines multiple calendars. Easy to use and customize. Also the free support on the forums is top notch. Within minutes of asking a question I had a developer and mod helping me fix my issue.