Being that I am in the transition even as we speak, I can give you my thoughtful perspective. First, I certainly would not advocate that anyone make the choice that I made. And it has absolutely been an enormous impact to my emotional life (for the good and for bad). On the whole though, I think its hard to make generalizations as our lives are not soley defined by our sexuality. I have certainly enjoyed the benefit of a stable 18 year relationship with someone I have been friends with for 28 years. There has been very little drama, we have 2 of the greatest kids you can imagine, and a wonderful home we've created together. Bedroom life has been an undisputed disaster and I don't down play that in the least. I make no pretense to being bi, cause I am not. Sucked a lot of tit cause that was the closest I could come to having a cock in my mouth (And thank god licking pussy did nothing for my wife cause I'd rather lick ass before ever doing that again).
On the whole, I seldom get sick; blood pressure, cholestral and all other vitals are fine; and have no major heath issues. Not sure the has anything to do with the path that I chose. I happen to be very active and eat well. I have also been open about my sexuality with my brother and closest friends for a number of years. Would have dealt with this change of life sooner if not for the kids.
Assuming this thread is around another 40 years, I'll report back on my life's expectency. Hopefully by then I can talk about how my 35 years of marriage to my husband, have further evolved my life.