Yeah, the stress is on "essentially". I'd take a big pay hit for a fellowship only if it empowered me with a qualification that allowed me to do work I couldn't otherwise.
If I did a residency in Internal Med, I'd do a two year fellowship in ID, because it allows me to be an ID specialist. A two year fellowship with EIS would be great experience, but wouldn't qualify me to do anything new.
Again, it's a great program, but I'd look at it as a service opportunity that gave you some fun experiences and some great job experience.