Want to throw in a few cents to this discussion.
I think in this community that *passing* itself is very hard to judge, knowing what we all know in here. I mean there will always be the starry eyed cd who says everyone who posts a picture passes. Then there are those with very critical eyes for only perfection who would say "no one passes". So the people to whom you are guaging reactions from on forums to me are always going to give a skewed answer , myself included.
Also my other thought on passing in the MTF scope is that...alot of times passing is not really passing, it is the kindness of strangers or people being polite and going along with what you are presenting as. People assessing what they see in that few seconds as you pass them by and deciding that they will buy what was presented because that was the desired intention. Or longer interactions where they realize that you want to be seen or treated or called by female terms so the polite person will do as they assume is wished...even though their brain starts calculating all the gender clues that don't quiet add up. The kindness wins over the logic of gender in this scenario.
Now as for the comfortable and confident thing...well yes, people who look liek they have every right being in the ladies restroom or shopping in the stores or being where ever they are will not get noticed or payed extra attention to. But that still I think does not necessarily indicate passing. Again, hopefully most people will not worry about logic and choose kindness over any reaction or confrontation.