I bought GT1,2,3,4,5 & 6 without thinking twice. With all the drama surrounding GT6, I have to say I'll be waiting when 7 is released before I spend my money. When comparing GT5 & GT6, instead of a step forward I think they stepped sideways!
GT7 is propably a made purchase for me, considering the potential GT6 shows. It is clearly limited by hardware, a fault on PD's account for going too ambitious perhaps, but the power of the PS4 combined with the intended vision of the GT franchise makes for a promising future.
For many, GT5 and 6 were disappointments. I do believe that the technical flaws can be ironed out by a huge leap in power. GT6 has the potential to look next-gen already, if only by increasing the resolution, increasing the car grids, perfect the lightning, and pushing the button to make the cars into the detailed models they were created as in the first place. Everything points towards a future-centric approach, with PD, instead of fixing this generations mistakes opting for the long run in order to make GT what it is supposed to be.
That attitude, I think, slapped many people in the face expecting the grandeur of GT being on display here and now. While it is a great and very enjoyable game, it reeks of untapped potential just not possible on current hardware.
So why the positive outlook on things?
The massive leap in hardware power and the preparation PD has done in order to move towards the next generation will propably pay off massively once GT7 arrives. The amount of time that had to go into optimizing, squeezing every bit of power out of the dated PS3, can now be focused on other aspects of the game. With technical problems (hopefully) out of the way, PD can focus on the GAME instead of the technology.
So, there will propably be a lot more time to focus on the sound engine, on the A.I. (also propably limited by technical problems) and on the game structure as a whole. At least 400 cars are already ready to make the leap. So are almost all of the circuits bar the original ones.
If PD does nothing to change this, then well, indeed GT7 won't be a purchase for me. But I doubt it. I highly, highly doubt it. Let's hope I'm right...