So, I know that this isn't C&V at all, but there are a lot of knowledgeable people on this forum regarding various tubing types, so I thought I'd ask. I'm looking at picking up an All-City Big Block track frame for the local velodrome. The website describes the tubing as "Our proprietary 612 Select double-butted cro-moly steel." Does anyone know anything about this tubing, or better yet, have you ridden it? What's it comparable to in C&V terms? I'm much more familiar with Columbus and Reynolds.

Here's the bike in question:


Dropouts are cool, too.