I have a 27" Dell U2713H.
Does the output differ much if I use the HDMI-DVI cable or if I get a Thunderbolt cable to connect the Mini?
Since that monitor is such a high resolution (2560x1440) you will need either a Mini-Displayport to Displayport cable or a Mini-Displayport to Dual-Link DVI adapter to connect it.
The Mini-Displayport to Displayport cable will probably be quite a bit cheaper than the Dual-Link DVI adapter.
Edit: I just double checked and the U2713H has a Mini-Displayport input, so you don't even need an adapter, just one of these: http://www.monoprice.com/products/p...=10246&cs_id=1024602&p_id=5991&seq=1&format=2
Yes i have this (the Apple one for $39!!!) I was thinking about returning to get my money back, but now If I can use it then maybe i will just keep it instead of traveling to an Apple store to return and order the cheap one and wait for it to arrive.