I have had a whole host of Logitech wheels from the original official GranTurismo 3 Force Pro -> Driving Force Pro -> G27.
The only issues I have had with any of them is when they get older the potentiometers in the pedals start to weaken and occasionally will flutter on when you arent touching it (on my DFP, the brake would constantly be pressed down very minutely). But these potentiometers are very cheaply replaced and available on ebay.
I very much vouch for the G27, if you shop around you will find it for nearing £200 which is a very good price. I am using the G27 for Project CARS and love it, although haven't got enough confidence to go to H-shifter controls yet. If you look on the Project CARS forums there are lots of posts similar to this with lot's of replies from people who have used the G27 and competitors with real insights.
For my purposes the G27 works a charm and wouldn't hesitate to recommend. I am not a hardcore sim guy though so cannot compare it's 'fidelity' to those of the Fanatec series etc.
Video of me battling with a touring car with the G27: http://www.youtube.com/watch?v=KQi5KlLEmkM