It's amazing how many people just skip over the board about steering wheels and the like.
https://www.gtplanet.net/forum/forumdisplay.php?f=163
As for your question. I played GT5 for a year with the DS3 controller. Then bought a Logitech G27 along with a Playseat WRC setup. Absolutely fantastic upgrade, and made a world of difference. Back in february, I sold my G27, and replaced it with the Thrustmaster T500 and the Thrustmaster shifter.
The quality is certainly a lot better, with the FFB being a lot smoother. However, if you don't plan to use it in anything else than GT5, then the difference in performance between the G27 and T500, isn't big enough. And as such, I'd recommend the G27.
But if you want to venture out into PC sims, where you can make further enhancements to the FFB settings, then no doubt you should go for the T500. It's miles better when it gets to run with a good Force Feedback engine, and completely blows the G27 out of the water. If you do go with the T500, I very much recommend getting the shifter as well. It's dirt cheap considering its quality.
So in short. If you only intend to use it with GT5, get the G27.
If you intend to use it for multiple sims, both on PS3 and PC, get the T500.
Fanatic wheels are also worth a look, though in my opinion, they are too expensive (talking about the Elite).
