What differences after transition? The first thing I noticed was that women were less guarded with me. I've noticed that when men talk with women, the women always seem a little wary. I doubt if they even notice it, but I think it's that they've had so many bad experiences, even with "nice" guys, that they're always prepared for the guy to do something that makes her feel unsafe. BTW, these were all women who had known me before transition. At my church, I announced that I was transitioning, and I noticed this with the women there.
Once I was fully transitioned (legally, socially, at work, etc.), I would sometimes walk out the door of my apartment and find myself exclaiming, "I'm so glad I'm me!" (This is very out of character for me.) This was mostly in the first year after I went full-time.
As for the mirror thing: I've never thought "I love you, mirror!" But I've never wanted to, either. At this point, I think I just look an average-looking old woman, good enough that nobody notices, especially since women become invisible after age 40 or 50. Back when I was living as a man, I developed this dissociative trick of looking in the mirror and not seeing myself -- I had no feeling connection with the image. Then, when I put on a skirt, I suddenly found I liked seeing that part of myself -- the part in the skirt. As I femmed up my wardrobe, I was able to see more and more of myself. And last year, after my SRS, I suddenly didn't mind being naked. I would look in the mirror and see myself -- an old lady, which I was comfortable with.