So, here's my dilemma. I've currently got a 21.5" iMac and a 15" MacBook Pro. I really want to get an external monitor for the MBP, but obviously 21 doesn't work as that. The iMac currently serves as our Media Server for our AppleTVs and I also use it to rip and transcode DVDs for our media collection. So my considerations are these: Option 1 I could get a Mac Mini and a Thunderbolt display and use the Mac Mini as the server and switch to the TB display for the MBP. The pro on this is that it's an easy solution for the situation and the Mac Mini can keep running the files for the media and even keep working on transcoding the video files while working on the MPB and using the TB Display. The con is that the Mac Mini is a dual core vs. a quad core like the iMacs which means that it will take longer to do the video conversions for the iTunes library. Option 2 Get a 27" iMac that can serve as an external monitor as well. It's what I wish I'd done originally, but the wild card for me is not knowing if it has the ability for the "computer" part to keep running while the screen is being used as the extended display of the MBP. It really needs to in order to serve the files and transcode files while I'm working on the extended desktop. I could flip back and forth, if necessary, but I could also access it by screensharing or remotely. If it doesn't keep working, that's a deal breaker and I'll go the Mini route. If anyone has insight into this, it would be greatly appreciated.