I have used Netflix for almost 3 years. It works excellent, so long as you follow the unwritten rule of not renting and returning too many movies in a given time period. I am careful to, at least most of the time, only cycle the number of movies on my plan once a week, or less. I have used everything from the 3 at a time to the 8 at a time plan. If I, for example, exceed this rule continuously for 1 month or more, it results in a gradual throttle of my service. Eventually, it becomes pathetic and slow. It took over 2 years of experimenting; and this happened every time I broke the rule. It takes some time(about a month or so) of following the rule to get the service back up to speed, or so it seems. Now, following the above always resulted in exceedingly quick service and having movies almost always available(as opposed to throttling the service and in addition causing many movies to be suddenly listed as 'short wait'). I currently use the 6 at a time plan. Assuming 4 weeks in a month, it costs me slightly under $1.60 per movie. A good deal if you ask me.
-Chris