Toe Box - As with the Instinct 1.5 I own, the toe box w/ the Olympus is welcoming. The Hokas are definitely narrower and hard to go back to when you have been wearing a wider toe box. The uppers on the Hokas feel more stiff.
Food Bed/Rocker - Both are very cushy but there is an interesting 'drop' at the toe of the Olympus that you feel when you first put them on. The Hokas just feel cushy all the way through. The interesting part is when you start running. It seems that the Olympus' "apex" (for lack a better word) is right at the ball of the foot where the Hoka feels like it is further back. I have to work to maintain a forefoot stride with the Hokas and I feel like I can easily cheat my form when I run. The Olympus, on the other hand, feels like there is little work to stay forefoot and I can maintain proper running form more easily.
Drop - As noted, I have been dealing with achilles issues so the 4mm drop of the Hokas have been helpful. The Olympus, of course, is zero drop and I can feel a bit of a 'twinge' in my left ankle cause my heel is going down farther. Clearly not enough saddle time yet to make a call.
Net/net - When I am done running with the Hokas, I want to take them off and let my feet "breathe". No such feeling with the Altra but w/ the drop, I will need to ease into them. Curious to see if others have tried the Olympus yet and their initial impressions.