[iPhone SDK] Nib vs. JIT allocation: memory pressure and programmer time

Question

I'm going to ask a question that there's no single answer to. Instead, I'm more interested to know how different people approach the same problem.
Lately I've been finding I'm of two minds when I have a UI element or view controller that isn't always used. On the one hand, the iPhone is a fairly memory-constrained environment, and the rules for developing for it are pretty explicit: don't use memory until you need it. That suggests "just in time" or "lazy" allocation: don't allocate it until you actually need it for the first time. After that, hold onto it in case you need it again, but be ready to free it if you receive a memory warning. My code is full of methods with names like "ensureViewerLoaded" which I call just before I need the object in question to allocate it if necessary.
(For context: my applications are generally UIKit-based utility or data-browsing/editing apps with little graphical or computational complexity and very little memory pressure overall. So far, I've only released one app; at its greediest, it consumes about 1 MB. This isn't because I'm a brilliant programmer--although I do try to be parsimonious--it's just because the app doesn't need much memory to do what it's supposed to do.)
But on the other hand, allocating those same objects in nib files (or, in other cases, loading them from plists or object archives) makes me more nimble. I've found that it reduces the weight of my code, paring it down to the logic I really need to be paying attention to. That lets me code faster--which means I can modify faster and release faster. And one thing I'm finding is that on the App Store, more releases means more sales. And more sales means I get to buy a MacBook Air with an SSD sooner, and thus save my back a few pounds of strain and my patience a few seconds of compilation. ;^)
I guess what I'm asking is, how are you resolving these sorts of trade-offs? Where are you trading phone resources for programmer resources, and where are you deciding not to? And how is the type of app you're writing influencing that decision?

Answer 1

My applications don't need much memory either, so I let everything happen in the nib file. I typically have about three views to worry about, and nothing significantly graphical in any of them.