Just to set the record straight on something first.... A 'sound card' implies an internally fitted PCI card or similar, which you can't do on a laptop of course. Audio Interface would be the proper term here, as per your thread title. Sorry if that makes me look like a pedant, but it makes things clearer for most folk
Ok! So first, do you anticipate recording multiple tracks simultaneously? Or would 1 or 2 tracks (stereo) at a time suffice? Same for outputs, do you need more than stereo for outputs? Like 8 or 16 outputs for example? You could playback say, 48 tracks inside the computer, but still only need a simple stereo in/out..
Secondly, How much of a fuss pot for sound quality are you?
Motu stuff is very good however. I doubt you would be disappointed with it. The sound quality is generally great, build quality is nice and the drivers are rock solid (Motu still support my 7 year old 828 mk1!)
So if you do happen to need multiple in's and outs, then an Ultralight would be great,
I've no experience of Native instruments interfaces however, so can't really comment on that.
If for example, you only needed stereo in's & outs, and also happen to want top notch quality, then interfaces like the Apogee Duet are also great. A little simple by way of features (No midi ports or digi Ins & outs), but then not everyone needs a high feature count (Firewire only too). They sound superb however. So its another one to look at perhaps.
If your mac has Firewire, then I would generally go for an interface that uses it, over USB. USB can be perfectly good, but on Macs at least, Firewire is that little bit more dependable in my experience.
