Sure cup and cone is fine, I packed grease in many of them when I was a teenage acolyte . However, I think the Tern makes nice use of standard bicycle components and as I'm polytheistic now I like to be able to mix and match. If I'm on a tour and have a mechanical problem it's good to be able to go into any bike shop and buy something from Shimano or SRAM and just install it. If commuting and trips on the Tube were all I was doing, then the Brompton's fold might make it the better choice, but I think I'll go with the greater versatility of the Tern and sacrifice a bit on the fold.
Looks like you found the right folder for you. Don't forget to post pictures when you get it ;-)