Both require proper preparation. Design is much more important than creation.
OO will almost always take more code than procedural, which logically equates to more time coding (minus tricks like IDE accessor / mutator auto creations).
Size of the project is irrelevant IMO. I can take any simple functionality and turn it into a more complicated OO implementation. Is it better? No, it does the same thing. Is it easier to use? Maybe. Is it easier to expand? Probably.
Best example I could think of is making a composite calculator where I can keep giving it new instances of classes to add additional functionality. This is relatively easy to do in OOP, but takes more effort to do in procedural. End result of add, subtract, multiply and divide in procedural would be about 20 lines of code to deal with the lhs, rhs, and which operation to perform. Compare that to 5 OO classes plus one interface. Even though each class is a single method with a single instruction in it, the end code wise is substantially more than 20 lines of code.
The real difference is so long as I built it correctly, adding a new operation is a simple matter of:
And it will build itself according to what I have designed. In procedural, I'd have to write the switch for the operation, the HTML for the input, etc.