> On the other hand, deferring non expected path to later using exception like you clearly state sometimes actually is good thing as it speeds up development time significantly.

Personally, I like the idea of Java's "checked" exceptions, particularly when your software involves lots of layers that need to use one-another appropriately, including adapting to error situations.

If you go "quick and dirty" with unchecked exceptions, you have the option to change them to checked ones later. When you do that a lot of stuff will "break", but really that will just be the compiler walking you through all the paths the exception could take, asking you to make a decision at each spot about what you want to do. (Pass the exception up the stack unchanged, catch it and wrap it and throw the wrapper, catch and recover, catch and ignore, etc.)