I'm also at 310 as this is the sole focus of my collection -- with the ultimate goal of a "playing years" card for all possible. Which, according to PSA, I'm at 249 of 272. Their "272" is not all encompassing but a good guideline for me at present.
I'm constantly upgrading and downgrading into cards I find more appealing. I'm partial to standard or smaller issues and not a fan of multi-player issues.
Following is a link to my registry set -- and I'm always looking for help
http://www.psacard.com/PSASetRegistr...t.aspx?s=77755
Scott