As a Netflix user since the early days (and a heavy Netflix instant watch user) I would say its IMPOSSIBLE to find a better deal. With that said one presons deal is another persons money waster. If your concern is new movies, not a good idea, basicly only Movies that are on "STARS" movie channel and some independents are ready to watch as they are released on DVD. Netflix as some stated, has got some agreements to have more NEW instant stuff, but the agreement (as far as I read) is that new releases will only be DVD only for 1-3 months (not weeks as some have said) then be avialble for Instant. So if 1-3 months is not to long, DEPENDING on who signed this with netflix (just one major studio as far as i know so far) it may or may not be a good thing. but there are 1000's of good movies I'm sure you have never seen I'm betting. ANd many series (again, as many have stated). I watch alot of series and didnt notice to many that had the episiodes on DVD only, in fact right now I just ran into my first (arrested Development, and its only the Pilot).
In my book it would get down to how many moves i rented, most rental places around here are $3 a rental on new stuff. SO Netflix is basicly 3 movies worth. I can easily get 2 movies (in the cheapest Netflix plan) a week from um (new DVD's), so that is $24 worth of rentals Of BRAND NEW movies. Then tack on the instant to watch stuff, cant see how it could be a bad deal for $10. So you get your brand new movies (but only by mail) and all the rest...
As for PS3 compared to 360 or Wii (or roku box or Netflix enabled device).. 360 is clearly the easiest of the 3 consoles, no disc. Quality and streaming, no difference that I can see, controls, that would be 100% prefrence, or opinion, they all work the same to me. But I would get a Roku box.. small easy to use and has more then just Netflix.
I honestly cant see a downside to a $10 neflix plan unless you are to far away from a disto center, dont have time to watch (which makes the whole discussion moot) or are so impulsive you cant plan a movie a day or two in advance (nopthing wrong with that, who knows when you will ahve time nowdays).