yeah you know what it is, for all this stuff there are 2 different standards, that is the EVC model and the IEEE model.
EVC = ethernet virtual circuit (something that the MEF, metro ethernet forum came up with).
the IEEE model is something you are likely most familiar with, it comes with the trunks and all that that IOS classic devices provide.
The a9k, wanting to be MEF compliant followed the EVC model which came with l2transport (sub)interfaces also known as EFP's (ethernet flow points).
Now when we're talking switches, we create an interface VLAN (or SVI = switch virtual interface), on a router the direct equivalent is a BVI (bridge virtual interface)
The good thing about the EVC model is that you create a bridge domain and you can pull in ANY vlan you like and effectively do vlan switching and vlan manipulation, it is way more flexible.
In an IEEE model an interface having a vlan 10 ALWAYS connects to another interface with a VLAN 10, something in the EVC model you don't have as you'll need to connect them together via a bridge-domain.
So EVC is more flexible, but requires more configuration.
In simple "theory" the EVC's bridge domain is the equivalent of a VLAN and you'll need to manually pull in all the EFP's (you know what they are now:) into that BD to link them together, which was something that happens naturally in the IEEE model.
I don't know either why it has to be that complex and full of TLA's (three letter acronyms) :)
hopefully this unraveled some of the complexity and namings...
cheers
xander
