Lowest latency Firewire audio interface for Logic... which should I choose?

Hi Guys,

I'm about to replace my trusty Yamaha n12 with a dedicated firewire audio interface.

My main requirement is super-low latency for running BFD and other virtual instruments, along with monitoring through Logic directly sometimes (to add effects to vocals in real-time, etc).

I've narrowed down my choice (I think!!) to:
- RME Fireface 800
- Apogee Ensemble
- MOTU 896 Mk3

I have been told that the RME drivers are incredible, and hence it has the lowest latency.

I'd love to hear from other Logic users who own any of the above! What kind of latency do you get (round trip in ms)? What is the lowest buffer setting you can use?

Any downfalls or problems you've had with any of these interfaces?

Thanks heaps guys, can't wait to hear some opinions!

Cheers and thanks,
Mike