I have an E. parviflora (formerly known as E. alata subsp. parviflora) and I have not noticed any scent from it at all, but that may be specific to the subspecies and E. alata may be completely different. I don't own an E. cordigera but I have come across it a number of times in shows and it is very fragrant and has a quite nice scent.
I have both and like the cordigera more.
Alata has a sweet scent but you need your nose in the flower to notice.
Cordigera scent reminds me of rose and can be detected a few feet away.
For both I think the scent was stronger when the plants were more mature. I don’t think either had much of a scent the first time they flowered.