Their licensing agreements change a lot, which is pretty fucking annoying. Stuff you've had in your queue will just disapear. Then, if they re-negotiate, it might come back. Their list isn't awesome, but be sure you're looking at your queue online via a web broweser. If you browse via a set-top box channel like Roku or WDTV etc, you might not get the full list. On my Roku at least, you can only ever get their 'predictive' lists, and 'popular' lists etc. I can't browse the full catalog unless I do it through a browser. Are you doing streaming only, or the DVD service too? They have a lot more on DVD.
I mostly use it for a few TV shows, and a lot of standards/classics I haven't seen yet. I've been bingeing on Jean-Pierre Melville and Wong Kar Wai, but a fair percentage are on DVD only.
I don't think I'd bother with them in streaming only mode, unless I was way more into TV.