I am in the "Need to Know" camp. In many forums you see a lot angst expressed over coming out. Perhaps how it's done has a lot to do with where in life you are? If you have a well entrenched and mostly working life, as little upset (aka notice) as possible always struck me as the best way to go. However once things become more "Official", as in name change or gender markers, it can/will have an impact in many areas of your life.
From what I heard from several members in my TG group people tend to be hesitant to say or ask you anything regarding changes. Once the rumor mill is fed everyone will be noticing every little thing about you. One member was well past the point of only fooling herself before she made it official at work. How other people act, think, feel, etc. you cannot control. There are also rules that need to be followed. TG rights, or "bathroom bills" are not all that common. Hence our legal protections are lacking. After having been in management, along with around the block a few times, I can assure you any employer can and will get rid of you finding some "legitimate" business reason to do so if you aren't worth the hassle. Only a PHB will say in writing it was over being TG.
Distant family and friends? Family will hear via the rumor mill. Distant friends have no initial "need" to know. Even not so distant or close friends really do.
On the flip side is the ever present "You are only as sick as your secrets". I occasionally anguish over coming out to my sister. Right now there is no legitimate need to, just an emotional need. I am tired of the shame, the guilt. Yet, there is a big risk in telling her anything right now to the only real family I have left. If / when going full-time is reality, then I will