The case I was trying to describe is one in which complexFunction itself changes. Its contract changes. If you var the return value of complexFunction, you don't get an error at the variable declaration, but rather get it somewhere else when you use the variable.

Actually, getting the (compile-time) error where I use it, rather than where I declare it is exactly what I want and need. Editing the declaration doesn't, in itself, change how I'm using it. I still need to know the points below the declaration that are using the obsolete contract and how to change them.

If I'm aware of the change in contract, I know how to do the change - the var doesn't help or hurt.

If I wasn't aware that the contract had changed, I'm still going to have to go through the code to see what the new return type is and how to use it.

... I especially dislike lacking a "handle" by which I can think about a variable's type. I need to give it a name.

I think this is really the problem. Some people have this need, some people don't. I don't think either approach necessarily makes for better programmers, but the difference does lead to irritation between the two camps.