I have found the streaming video is hardly useful. You have to select an option from a limited amount of choices and most of the choices that you have in mind are never available. When browsing the selections available on the PS3, either luck or a compromise is likely necessary to facilitate a movie-viewing.
The mailed disc side of the Netflix experience is the better side of the coin. I upgraded to Blu-Ray for a couple dollars more and can watch as many Blu-Rays as I can get mailed and mail back. That is, it takes a day or two to get it mailed, then takes a day or two for them to get it back. That being the case, I can probably get about 6-9 Blu-Rays mailed every month. The setbacks are the delivery delays (snail mail is nicknamed for a reason), unavailability due to demand and the fact that the release dates for the Blu-Rays are not the actual release date for the video of popular movies. Therefore, most new releases are available at least a month after their actual release but demand could make them impossible to get until even longer.
I like Netflix overall, but these setbacks can be a little annoying and I wish I knew what they were actually offering before I got sucked into the hype.