I currently have an old 21 inch iMac that won't run Lion because it doesn't have a 64 bit chip. Other than that it works absolutely fine. I am however a part time developer and so I really need to make sure I have a machine that runs Lion for testing as a minimum.
Looking at new Mac minis they seem ideal to solve this problem being relatively low priced and able to do a few other things I'd find useful. My question is if I just get a new mac mini, could I somehow use the existing iMac as a monitor for it by using for instance screen sharing software. If I do then what will the performance of the screen be, I'd only really like to look at this if the screen sharing looks the same as if I had connected a monitor directly to the mac mini.