Never mind on the Mackie; it's USB 1.1
 
But...
What about the TASCAM US-2x2? It comes with Sonar, so it should be a good bet, right?

I myself picked the Scarlett 6i6 over the 2i2 and the 2i4 because it has a power supply. I have read about lots of issues with using USB powered interfaces. It's just not enough juice to run the pre amps and especially 48 volt phantom power. On some systems they report a grounding issue too... Go with the Tascam if it comes with a power supply. 
 

+1 ^^^
 
The US-2x2 is USB-powered. The US-4x4 has a power supply with a switch inline with the power cord. The US-16x08 has a power switch on the front panel!!!
 
My US-16x08 showed up last night. I'll be installing it shortly. My PreSonus AudioBox 44VSL will be relegated to mobile recording, using the Audio Evolution Mobile DAW running on my Google Nexus 10.
 
I was waiting for a sale on the US-4x4, but when MF put the 16x08 on their Stupid Deal of the Day (for $50 less than the 4x4 and $100 less than everyone else's price on the 16x08), I jumped on it.

Cactus Music
I myself picked the Scarlett 6i6 over the 2i2 and the 2i4 because it has a power supply. I have read about lots of issues with using USB powered interfaces. It's just not enough juice to run the pre amps and especially 48 volt phantom power. On some systems they report a grounding issue too... Go with the Tascam if it comes with a power supply. 
 

Interesting. Perhaps the USB power is why there are bad reports floating around about the lower-end versions.

USB bus powered interfaces do seem prone to problems. Or at least, people who have them seem to turn up in forums asking about various problems.

Maybe one issue is that not all USB ports and sockets are created equal. Although they are supposed to carry a certain level of amps/watts not all do. It's quite common for PC motherboard USB not to have enough current to do more than barely trickle charge a switched on iPad for example, though Macs and some PC motherboards have no problem. If the power from the USB socket is marginal then that might explain things, especially if an interface is designed with the Mac market in mind (Macs seem to have more juice at the USB sockets).

Unless absolute portability is a requirement going for an interface with its own power supply is probably the safer bet.

It's also worth making sure any interface is certified by the manufacturer to work properly with USB3 sockets. Not all do, especially older designs. USB2 is still around in the PC world but it's probably only a matter of time before it disappears on new boards and laptops.

Focusrite Forte is superb, heads and tails above the other focusrite offerings.

tlw
It's also worth making sure any interface is certified by the manufacturer to work properly with USB3 sockets. Not all do, especially older designs. USB2 is still around in the PC world but it's probably only a matter of time before it disappears on new boards and laptops.

Good point.
 
Since I'm going to be getting rid of my desktop and going to a notebook soon, I'm thinking this is a good reason to hold off on buying a new audio interface for now.
 
Thanks.

Vastman
Focusrite Forte is superb, heads and tails above the other focusrite offerings.

Sure does look sweet. I don't have the money for something like that ATM, though. :)

I think you should be able to pick one up at GC for around $300 during their sale... just find a manager and talk to um... it is truely amazing, the best sounding mic pre's ever (I'm a singer) and the Direct ins are just ****en.  Haven't used a db since.  And it is glistening.  I still have several interfaces and auditioned a few others like the Audiobox 44 and presonus thingy and they were all just dull compared to the advanced rednet based pres... kicks but on my old focusrite pro-24dsp units (I've have two of them...plus an NI audio4 plus the big nice emu package...)
 
I can't ever imagine upgrading again.  
do it once... do it right... just wangle a deal!
talk to cclary... he'll agree!  

He is using a Mackie mixer so the pre amps are not on the agenda. When you use a audio interface's line inputs you are by passing the pre amps. So the topic is still, a low cost interface that has good drivers. 
Why worry about interface pre amps when adding better quality is easy and not supper expensive. 
 This is why I bought a Joe Meek ThreeQ. I don't like the Scarlett's Pre amps but I'm OK because I never use them. I use the Joe Meek for 80% of my work. When I have other musicians in the studio I sometimes use the Mackie Mix 8 pre Amps and they are also way better than the Scarlett's. The Mix 8 was only $65. Can you believe it has replaced my $2,500 Yamaha 01V ? 
 
 
 The Scarlett 6i6 pre amps are overly sensitive and clip at the drop of a hat. You end up recording at way to low a level. Maybe the high end Focusrite interfaces uses better pre amps but the Scarlett's fail to please.
 You can hit the Joe Meek or the  Mackie hard. My old Tascam us1641 was the same way, it could take abuse and not clip. But the Focusrite drivers are better than my old Tascam so there you go. Drivers are paramount to me. So from my point of view, if the new Tascam interfaces now have better drivers and they also sport what the Craig claims are very good pre amps.. then ? Seems simple to me. 
And wouldn't the Steinberg be using cheaper Yamaha pre amps? But if the drivers are good then that's another pick.