I know its won't be popular with the ab initio crowd, but give me a high time guy. The progression to the right seat of a large jet in the US in via the military or through regionals. Either way, by the time they make it to the right seat, they have been Captains on a complex turbine aircraft. Thinking like a Captain is something that can only happen with experience. The monkey skills of IFR are easily learned, thinking like a PIC is not.