Digital device recording, digital or analogue?

[Amphibian]

I'm just about ready to pull the trigger on a brand new DAW recording interface and I have narrowed it down to two options:

1. RME FireFace 800
2. Apogee Duet

My question is this since I'm planning on using it with a digital device called the AXE-FX... What is the best way to record a digital device like this? Digital or analogue? The Apogee has all I need in a project studio interface: It's made for MAC, has great sound quality, a low noise floor, a gentle price tag and no frills; all but a digital I/O (which would've made it just perfect). So what I'm wondering is if there will be any audible difference between the great quality of the Apogee DAC and the alternative with digital inputs, namely the RME FireFace 800?

Is there some sort of stand alone digital I/O one can use with the Axe-FX and as an addition to the Apogee?

I hope I'm nut busting chops with my questions. Thanks guys, much obliged!