The hard drive can be used for installing your games on from the discs. (You still have to have the disc in the player!) It is faster for some games that are optimised to run off the hard disk. As for the 3D Blu-ray as I understand it all current PS3s will be getting a software update that will enable the 3D Blu-ray functionality. In fact it might have already happened.
More disc space is better, but there is an obvious price difference it comes down to you really which model you go for.
The hard drive can be used for installing your games on from the discs. (You still have to have the disc in the player!) It is faster for some games that are optimised to run off the hard disk. As for the 3D Blu-ray as I understand it all current PS3s will be getting a software update that will enable the 3D Blu-ray functionality. In fact it might have already happened.
More disc space is better, but there is an obvious price difference it comes down to you really which model you go for.