I've tried racket/typed before and my knowledge or experience with it might be outdated, but sometimes I just could not get it to agree with my code. I fix one typing warning or thing it cannot infer and another would pop up. I fix the other, then a third pops up. I try to fix the third one, but realize I cannot and need to go back to the original state. When such things do not happen, it is very cool though. The code behing typed racket for me seems so mind bogglingly complex, I did not dare to investigate further. It is a language composed of macros, which use rackets macrology stuff, which is already more complex than other Schemes'. That language can be used to design any type system as far as I read about it.
With my typing trouble I should have come to the user list and asked, but I dId not, frustrated and thinking I was too stupid to get it ^^'
I did once at least see a question on the mailing list, where the answer was, that typed racket could not do it, as in infer types, so it might not be perfect yet, or perhaps it did improve since then.
I wish more Schemes could just copy the typed part of typed racket, using that macro language, as in theory they should be able to represent it, but I guess the devil is in the detail and slightly different workings of macro facilities.