after researching online a little, I went to a local store and tried on a bunch. turns out the Icon Airmada is 'long oval,' fit me well, was pretty affordable, and build quality seemed high. I tried the HJC IS17, which says it's 'intermediate oval' but it must be on the long side of intermediate, because it fit well, but I hated the mechanism for the sun visor. Shoei GT Air fit pretty well too, but it was a little short front to back for my skull.
It just showed up on Friday so I haven't had time to put any miles on it, but it's pretty awesome looking so far:
http://twoslow.com/2017/04/icon-chantilly-helmet/I'll have a more indepth evaluation once I get some ride time with it.