Thing is, the PS4 is going to go to the XBox's subscription model for online. Currently, the PS3's online features are free, so now's a good time (we've probably a two to three year window for PD to keep up the GT6 PS3 servers) to pick up a used PS3 and GT6. Your wheel will work just fine with it.

GT6's AI has got quite a bit better, but it still doesn't challenge you a lot if you have good skills, so I can understand why, on the GT4 game, you tend to want to race alone (because of the AI, no reflection on your skills). But if you are a fan of the SPORT (rather than simply a 'gamer'), I can't imagine how anyone could turn down the chance to race against other skilled drivers...

But, each to his own.