Unless Sony decides to let you store games on the hard drive like the 360, there's no benefit to the larger drive units. And if you decide later to start downloading a lot of old PSX games, movies, and whatever else, you can always add a larger drive. PS3 has a fairly easy to replace 2.5" SATA drive. Think people have gone up to at least 500GB without issue.
Trying to decide which Playstation 3 System to purchase ,$50 more for 250GB not a deal Breaker .....any significant advantage to get upgrade if i am not storing TV shows or Movies?

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