I work on a team of about 10 people with Python on a pretty complex project. We have not experienced any typing issues in deployed code. I think this can be attributed to a combination of strong unit tests and type enforcement when constructing objects that are eventually serialized to the database. Python is stronger than some other dynamic languages at type enforcement too.

I believe I would prefer compile time type checking, but when working with a lot of dynamic data structures (say, JSON or XML) there is an ease that dynamic language toolkits can bring that a lot of the time evade more formal languages.