If you need a huge hard drive, sure.
The 500GB is the largest stock model they have, but you can easily upgrade the hard drive size with any laptop hard drive. If you're a new user, you'll have a very hard time filling it up, unless of course, you like to buy full retail games digitally, and then you'll need the huge hard drive.
Plus is basically a rental service, and this bundle comes with a year. A fresh batch of games are every month and you get them at no additional cost, provided you have the subscription. However, if you want to play those games after the initial year, you'll have to continue to pay the subscription. Once the subscription expires, you can't play those particular games until you resubscribe.
For an example of the free games, this month Plus users get Demon's Souls, Malicious, Zombie Tycoon, and a few others. That's on top of the other currently available games like Vanquish, Darksiders, inFAMOUS 2, LittleBigPlanet 2, etc...
Then on top of that you get The Show 13, which is arguably the best sports sim available(if you like baseball).
Whether you need that big of a hard drive is up to you, but I would recommend Plus to a new user, simply because of all the content that's available to you right off the bat.