In typical urban terrain by far the Carryme is most efficient with the caveat that the speed is limited by my ability to spin fast enough. In theory the gearing of the DT should have the advantage at speed, but it's not that great because at equal gearing it's much more difficult to achieve and maintain speed with the DT. So while on the open road the extra gearing starts to earn its keep, for stop and go the Carryme is king.

Any differences on other types of terrain I think relates mostly to tire diameter and width. I run 2.0" Big Apples on the DT, the stock Carryme tires are 8x1.25", and my 700c bike has stelvios and on reasonably smooth roads (not perfect, but what I would consider average) I don't think tire size makes a big difference. As far as below average terrain, rough surfaces with many small imperfections are best with the 700c followed by 20" BAs and finally 8". Grass is also best with 700c, difficult with 20" BAs and almost impossible on 8". Wide tires like 20" BAs are a must for unpaved paths with sand or roots and, although 700c can do hard packed trails, 8" are for paved roads only. However, on paved roads with large obstacles such as curbs and potholes neither larger wheels nor fatter tires help and smaller diameters win out for being nimble enough to lift, wheelie, or steer around in order to reduce impact or maintain control. So I find the CM best for urban assault, 700c best for long stretches on highways with fine roughness, and 20" BAs best as an all arounder (or offroad).