I am really interested in using Unity3d to develop an app. I like the fact that I can develop once and port the app to multiple platforms (Mac/Windows/iPhone/Android), and the performance on my Mac seems to be quite good.
This will be the first time I write an app for iPhone, and I am curious about performance issues down the road. I think I will definitely use Unity3d on iPhone for a prototype, but am wondering if building an iPhone Unity3d app will use the iPhone resources as efficiently as a native app written in Objective-C.
The Unity3d site seems to suggest that Unity3d algorithms are optimized, and I thought that if I asked that question in the Unity3d forums, that would be the kind of response I would get. Ideally, I'd be interested in hearing from someone who has built an app in Unity3d and Objective-C and can compare the two.
The discussion that got me thinking about this was Andrew and Peter Mortensen's response to a question about iOS development cost, which begins "There is a much easier way to develop iPhone apps than learning Cocoa."