I noticed this thread is now 2 years old - So I've started a new one. I needed a high res screen for graphics and same screen for racing. After much research I just bought the Hazro 27 WC LCD screen (2560 x 1440) 6ms. and Screen lag less than one frame - so in practice none! Same screen as the Apple Cinema at less than half the price at just over £400. I'm finding it excellent both for iRacing and rFactor 2 and also FSX. I'm using Nvidia GTX 295 (non Sli Mode) CPU is an i7 920 2.67GHz. and you can run it at lower res if you need to. From my experience so far I would highly reccommend it.
