I much prefer folks to use their real names where ever possible. All the serious collectors here tend to sign off with their first names. I do find it a real turn off when I help people with just a username and they reply just with this. I too am old fashioned and prefer a personal approach.
But I do understand that some folks due to "PC" considerations and their jobs prefer not to use their full names and we need to respect that.
I do agree about the avatar. Which shows how strong an effect an image has on the mind: if someone changes this it really throws you!