EDIT: see the problem i have with your post is its tone and refusal to read what i actually wrote. if you read it properly i am not saying anything different to what you seem to be saying: if you are a good programmer you can be productive in any language, including lisp. if you are a crappy programmer, knowing how to write lisp is not going to save you. knowing how to write lisp is trivial. even implementing some (minimal) dialect of lisp is not too difficult
on the other hand, i think that repl-driven development that is available to many (all?) common lisp implementations is unmatched in any language, and i think that this is unique to common lisp. please see the post by mikelevins in this thread that details this process. i think this can be a great productivity booster for production as well as exploratory programming. in any event i enjoy it a lot
… crickets …
Still waiting :)