When it's just you, you won't feel any difference - both will be perfect.
I've tried a lot of different interfaces in different categories with regards to price and features, and find that I prefere two brands: Apogee until the price point of a Metric Halo ULN-2, from there on I preferre MH. Both brands sounds really good, have really good software and drivers and integrates perfectly with GarageBand and Logic as well which is important for your workflow.
I've used and still own the original Duet with firewire and it's been perfect - highly recommended - but I've now upgraded to a MH ULN-8 which is absolutely unreal.
So depending on your budget and needs/wants I'd recommend either a MH product (ULN-2 or ULN-8 ) or an Apogee Duet (or perhaps even Apogee One).
The Apogee is really great and you have to go to the absolute top of the foodchain (MH, Prism ect.) to get something that's clearly better. Otherwise it's more about I/O's and other features.
The MH is stellar and also include DSP production efx's and MH's proprietary channel strip and preamp modeling called character. I love both the channel strip and character, and it could save you from getting into the merry-go-round of buying preamps and EQ's just like the Axe saves you from merry-go-round of buying guitar amps.
Hope this helps
RB