As a Sirius/XM subscriber, I have to say that this is a great app to have in my menubar. I could log into my XM account through the browser, of course, but this is always there, whatever I am doing on my computer. It is very easy to use. The streaming is just as good as if I were listening on my XM radio. So far, it is so simple to use, I have had no need for any documentation or support; just start typing in a channel number and it shows your choices. You then just point at the desired channel (complete with description, of course) and click and the streaming starts. If you need to see the title/artist information, you have to go up to the menubar and click on the icon; some people might desire to see this info in a crawl in the menubar, but I have too much up there already, so it isn't an issue for me. This is a must for any XM subscriber.