My therapist posed the same question, and I had actually made a pro/con list before I had ever seen her. I think I might have posted a similar topic a year ago or so. Frankly, I never got much of a "pro" list together, and I never could really answer her question; I just knew I needed to transition.
I'm pretty much smack in the middle of transitioning, with my life really hard right now, and I think the pros outweigh the cons by a landslide: better friendships, much less pain when I see the students returning to campus, no worry about going bald of getting more body hair, less aggressive sex drive, female climbing partners, etc. Definitely worth the cash and the HUGE hassle.
But I don't think the point is to get a big list together, but to teach you that where you are right now, it's hard to tell what you might get out of transition.