This is really interesting. I went from an eGo connection to a REO 510, so have never really compared 510s. Pretty cool.I did not realize how superior the 510 on a REO was until this weekend. A friend had a dna squonker and was fooling with it. It was impossible to get the air slot of the atomizer positioned the way he wanted it. The REO, of course, was no problem. The "O" ring trick from the old days wouldn't work because of the atomizer 510 length. This was no problem on the REO Grand, a twist of the hollow feed screw and it worked like a charm.