Script Optimization for mobile apps

I'm new to Unity but have been developing software for 20 years (c,c++, objective C, Java). I have always written very small functions and methods -- usually no more than 10-15 lines. For a mobile app -- in general -- is it better to have fewer larger methods or more smaller methods in C# scripting?

There's quite a bit of information scattered arround the Unity forums/ external sites, you just have to google for it. For ex.:

http://forum.unity3d.com/threads/16736-few-question-on-script-optimization?p=115082

http://www.cratesmith.com/archives/183 and so on. There's really quite an abundance of script optimization threads and posts.

It would probably be best if you start with the official Unity iPhone script optimization doc:

http://unity3d.com/support/documentation/Manual/iphone-Optimizing-Scripts.html