Oh man I wish I'd seen this yesterday. Od first all the way.
The od will do a lot more than just give you a highway gear. You can split all 3 speeds.
You know that 2-3 hole you have to dig yourself out of or rev 2 to the moon? It's gone with the od. 1-2, 2+od, 3, 3+od. Also for the odd times you want a little more than 1st use 1+od.
I'm running a basically stock 152, a dialed 1904 and have no issues at all keeping up with traffic other than up big hills where I shift to 3 straight and floor it up hills.