Should I purchase a PS3 for GT5P?

First of all, let me say I'm a huge fan of the GT franchise. I've played all of the series since the first simulator arrived on the PS1. I'm a car enthousiast. And I would feel bad if I didn't buy this game.

I have a few concerns about the game however.

I've been searching youtube also for some GT5 uploaded video's. I noticed a huge lag. So much lag the game would be unplayable like this. When I buy the system including the game. I expect zero lag!

I currently have PGR4 for my 360. And the game runs incredibly smooth with absolutely no lag whatsoever. Yes I have to pay for the online service, but in my personal opinion its worth the money.

Also. Will the Prologue have licenses? I loved that aspect of the game. Licenses are my favourite feature of Gran Turismo. I hear they deleted it? That would be very disapointing if it were true.

The thing that fascinated me about the creator of the GT series (Kazunori Yamauchi). Its his passion his games. The high budget composed music in the GT4 intro. The game really shows you the beauty of cars.

http://www.youtube.com/watch?v=iDcGFlEyBug

How is the difficulty of the game? I like my racers challenging. I hope they haven't casualized anything?

Thank you for time!

PS: sorry for not linking the url. Glitchspot keeps giving me HTML error for it.

Why is it so hard for people to decide on their own whetehr or not to buy a ps3? It's not that hard to do.

PS: Buying a ps3 for one game is kind of a waste.