I've loved the GT series since back in 1999 when I got GT1 and later GT2, GT3, GT4, and now GT5. I've spent countless hours in all of them. However I feel like PD wasted too much time on GT5 and I noticed that GT5 really isn't that much different from GT4. I hope Forza 4 will show great advancement in the simulator genre so that maybe PD notices that they could doing a much better job and then someday when GT6 releases it will leave me breathless.
Unfortunately I'll never have a chance to play F4 since I don't have a 360 and don't plan on buying one just for Forza 4. >.
^_^