I have a Fanatec Porsche 911 Turbo wheel with the standard wireless pedals.
The wheel is truly superb; excellent build quality, amazing force-feedback and almost silent belt-drive motor. The size and thickness of the wheel allow for a perfect racing grip (one of the reasons I chose this wheel over the G25, whose rim is too thin for my taste). There are plenty of buttons, all sensibly placed (another plus over the G25). The quick release clamp system works perfectly on my desk (but apparently not so well if your desk has a lip). I turn off the 'rumble' motors built into the rim, as they're not utilised by iRacing yet, and their default setting doesn't add any immersion for me.
The H-Shifter and sequential shifters are excellent, but the mounting system (two rods running through the wheel) torques a little too much when you change gear hard - especially noticeable on the H-Shifter.
The standard wireless pedals are good, but not great. The progressive feel on the brake pedal is excellent and really helps with brake modulation. The clutch also feels very realistic. However, the throttle is a little too loose for my taste and feels slightly flimsy (it clicks occasionally when you hit full throttle).
The drivers need a little work; I'm running 32bit XP and have to open the Porsche Wheel properties dialog to load my desired settings every time I re-connect the wheel after a reboot. Apparently a new driver is coming out very soon, so hopefully these minor issues will be fixed.
I only drive iRacing now (once you've driven on their laser scanned tracks, it's practically impossible to go back to any other sim), and the Fanatec wheel is 'fantastic' in iRacing: accurate, wonderful force-feedback and no center dead-spot all help to make me a little bit faster.
I plan on upgrading to the club sport pedals as soon as they hit general release. The Sim Racing Tonight review of these convinced me that I have to have them.
I've only used a G25 briefly, but I thought it was also an excellent wheel. In my opinion, the standard pedals are slightly better on the G25, and being able to mount the gear stick separately is a plus. However, the rim thickness, center dead-spot (which apparently can be reduced with a 107% FFS in the Logitech profiler), and overall feel of the G25 compared to the Fanatec made my decision pretty easy for me.
Bear in mind that the cheaper Carerra wheel is gear driven (not belt like the Turbo and GT3 RS), which makes it much noisier. But apparently the force-feedback sensation is still excellent.