What happens once you graduate from McKinsey OEP program?

Hi all,

I'm currently interviewing for the McKinsey OEP program to become a junior specialist. 

As I understand from the job title this should be on the expert track but from a few people that I've seen on LinkedIn, the OEP graduates seem to have integrative job titles while others have expert. 

McKinsey's own website makes this even less clear since they say “We already have OEP graduates working at all levels of the firm from associate to partner" - no mention of expert or specialist…

Is it the case that OEP allows you to choose between expert and integrative - in that case when does that choice occur? 

Also if anyone has any thing positive (or negative!) to say about the OEP then I would be interested.

Thanks!