I have a slow machine for now (2009 MBP), and Cappuccino is dog slow on it. I'd try it again in a heartbeat once I get a faster machine, but for now, it's literally (and I'm using that word right) unusable. A 30+ second delay after I save a simple interface in Xcode and the changes compiling. It's just frustrating. But if the turnaround time was less than a second, I think I would love to use something as "well-thought-out" as Cappuccino.