I finally dropped the cash for an Apple Thunderbolt cable. It’s not every day that I decide to spend $50 for one cable but it does add some functionality that I will find useful. In my case I purchased it so I could use my iMac as an external display with my MacBook Pro.
From time to time I need to be able to do some work that is more efficient when using two displays. This occasional setup will also save me the trouble of needing to setup a spare monitor somewhere else in the house (such as the dining room table).
Note that I’m connecting from a MacBook Pro with Thunderbolt to an iMac (also with Thunderbolt). If you’re trying to mix Thunderbolt and Mini DisplayPort connections it probably won’t work though I haven’t tested this extensively.
There isn’t much more to write about the cable. It costs $50 and seems to work with my gear. I didn’t notice any problems involving flickering, refresh oddities, or graphic artifacts.
To use the iMac as an external display just hit Command + F2 to set it to Target Display Mode.
One note, for those using gfxCardStatus you will need to make sure you’re MacBook Pro is using “Discrete” graphics. It will not work with the integrated graphics, just as the Mini DisplayPort adapters also won’t work in that mode.
Updated 07/18/2013: This setup works fine though I haven’t really used it, or the cable, since this post. I’ve been very disappointed with the implementation of Thunderbolt in general. Thunderbolt devices are still prohibitively expensive and I’m frustrated that there doesn’t appear to be any kind of USB 3.0 adapter available short of some very expensive docks (many of which have bad reviews).