If I was in your shoes I would have bought the G27 no question about it. Wheels don't last forever and it could easily be 2 years before GT7 is released so you'd get a good 2 years worth of gameplay from the G27 before having to upgrade. There's also the chance the wheel might be supported in GT7. If you get near release of GT7 and the G27 still wasn't supported, there might be other options besides the T300 at that point. I believe you can also get a dongle that lets you use the G27 pedals and shifter with the TM wheels.