There's a tempting $200 G27 online...
If you are an ex-racer that is probably your best choice, I have a DFGT and while it fits my budget and needs very well I admit it may be a little too plastic for some people (but has a very usefull D pad for navigating menus) and it lacks a clutch by default, I read reports of people sucessfully replacing the pedals of the DFGT with better ones so chances are the G27 (made by Logictech, same as the DFGT) may be improved.
The G27 looks like a serious wheel by just looking at it (I have inspected one, but didn't trial it "on track"), has some real neat paddle shifters (the ones in the DFGT are mini, but I happen to reach them just fine), the gearbox is on a standalone unit and can be configured for manual or sequencial shifting (on the DFGT you have only a sequencial shifter that is atached to the right side of the wheel) and the pedals are made of metal (full plastic on the DFGT), the wheel size is generous, much larger than the DFGT (oddly enough, the size of the DFGT wheel was about the same size of my Civic wheel) and seems to be more light on turning, the DFGT wheel, even with the FF engine off (you will need to learn this trick if you are planning on taking your G27 for a spin in some earlier Papyrus sims) doesn't feel completly free. One word of note, it may not be completly fair to compare the DFGT and the G27 (or it's predecessor the G25), the DFGT is essentially a wheel made for Playstation 2, so it looks consolish, but I hear a lot of praise for the DFGT for it's price tag and performance, I supose the fact you can mod it also helps and of course it's cheaper than the G27.
My personal opinion is that the G27 is for more serious people and the DFGT is for people who want a good wheel but can't or don't want to spend money for a top of the line wheel that they probably won't use to it's fullest anyway.
I haven't touched iRacing for some years (quit before the Mazda and Streetstock came along) but to this day it still is the only sim where I felt my DFGT was being used to it's full.
One word of warning, pedals seem to be sensitive area on these things, I can confirm the strenght of my DFGT pedals isnt right, the brake is probably ok, but the accelarator spring is so weak that it's hard not to floor the pedal completly. I would assume the springs on the G27 are better, but don't be surprised if you dont find those to your liking.
One last thing, I hear Logictech will stop making those wheels.