I'd certainly need a FR. My complex flying was done post '97 so technically, I would need a competency check with a FAA CFI. Having said that, I can prove competency due to my logged time in the Yak (and recency) so would it just be a matter of a CFI signature?
That said, the complex types I refer to are some pretty heavy metal and I wouldn't be let loose on them without some training anyway.