I think I've certainly been guilty of internally judging the looks of other trans women, but those are my thoughts, they are often human nature, an instant reaction rather than logical evaluation, and I would never ever air those thoughts. Support groups especially should be a safe place where looks are off the table as far as discussion goes. Same goes for here; outside the threads asking for critique (which are actually always honest but fair and constructive) then we should be supporting each other.
Now for me, personally, passing does matter, to me. I don't have the confidence to do the whole 'screw society and it's outdated mindsets' thing (although I applaud those that do), I just want to blend in and live my life. Whether someone else passes or not doesn't change how much respect or tolerance I show them; if someone presents as a woman, I'll treat them as such. But it would, I'm ashamed to say, affect the chances of me hanging out with that person. I don't really mean people who nearly pass but just don't quite, because I've met some trans women who don't 100% pass but just look great. I mean some of the older transitioners who dress inappropriately and look and sound a long way from female. Like I said, I'll still treat them with respect, but I have found myself turning down an invitation to ride the night bus through the city with such a lady, simply because I didn't want to be in a position where I could become a target. It is a reflection of my own insecurity and it's really not something I'm proud of, but its taken me a long time to get to being able to have any confidence in public so perhaps I still have some personal growth to come.
There's another point that's been made on this thread that I do have strong feelings about, and that's the 'you're not feminine enough' argument. I wear jeans 98% of the time, usually just with trainers. I ride a motorcycle, and I like football (soccer) and violent video games. I get really annoyed when other trans women feel that they can pass judgement on this and try to tell me that I should be smiling all the time, or gliding gracefully into rooms. It's an outdated and frankly strange version of womanhood. And some trans women do come across as strange pastiches of what they think a woman should be. I'll never say anything to them, I'll even smile politely when they do suggest I wear heels more (or, as one support group member actually said to me once, that I should hold back on expressing strong opinions in public) but it really p***es me off. I am me, and I started this process so I could live a life true to myself, not to fit in with someone else's expectations of who I should be or how I should act or dress.