I finally broke down and bought cubase sx3 about a month ago after years of using adobe audition. I have to tell you, at first I hated it. But only because it's so completely different from adobe, which was the only thing I knew and loved.
BUT, after lots of reading the HUGE manual, and after lots of trial and error, I'm finally getting the hang of it... AND, I would never ever go back to adobe at this point. It's so much more powerful in what it can do. And once you get into playing with midi and vsti, there's just no looking back. Not only is it a whole lot of fun, but it's jump started my creativity as well.
To answer your question, I personally have had zero problems with installation, or with the dongle, or with stability, or with anything at all. It's been all smooth sailing here. Of course that doesn't mean you'll have the same experience... I'm just telling you mine.