I don't known if was already said, but today i have found this article that speak about Dendrobium Superbum (now known as Dendrobium anosmum) and she said:
Oncidium Sharry Baby ‘Sweet Fragrance’ said that the scent smell of hot chocolate with just a slight taste of vanilla. And even this:
The sweet scent of the flowers of Oncidium is so "intoxicant" that in some cases can also be regarded as excessive.
Nice!
hehe - I have Onc. Sharry Baby 'Sweet Fragrance' - and it's a very strong fragrance - mine was outdoors while blooming, and when I was out there watering, even a few feet from the plant, it could be over-powering - and that was only with one spike, and it was actually quite fragrant for several weeks