Of those choices I would go with the newest Firewire 800. The current standard Firewire transfer rate is 800Mbps. vs. the original Firewire @ 400 Mbps.

{note the lower case 'b' in Mbps is bits, not bytes}

Online Information:

USB 2.0 has a raw data rate at 480Mbps. Although USB 2.0 at 480 Mbps sounds faster than FireWire at 400 Mbps, in reality no device on a USB chain can use more than two-thirds of the bandwidth. That means that USB 2.0 throughput tops out at 320 Mbps - 20% slower than FireWire 400.

References: (Credit where credit is due) The article is a couple years old, but still answers your question.

http://lowendmac.com/macdan/05/1007.html

However, we may be about due for a newer faster protocol. I would do some research and see how far off any emerging technologies might be from hitting the market.

Forget the bitrate, as long as you are considering USB2.0, FireWire400 or FireWire800. They are all theoretically fast enough. In both USB and FireWire, the data is wrapped up into packets that are transmitted at the prevailing bit rate. It's the gaps between the packets that determines the usable maximum throughput.

That said, there is a good reason why most multi-channel interfaces are FireWire and not USB. FireWire is a peer-to-peer protocol and can stream reliably from interface to disk at rates higher than a host-client protocol like USB.

Interface manufacturers have an interest in getting their products to work problem-free in the way that the users expect. USB is fine for two channels. For more than that, go with the flow and use FireWire.

If you have no urgent need for an interface it might behoove you to take that cash burning in your pocket and put it in your mattress for a bit more. Add to it occasionally.

The USB 3.0 protocol is nearly ready to be available to the market. The articles I've read predict (optimistically perhaps) trickling onto the market beginning in the new year. USB 3.0 protocol should completely outstrip all the other bus types if it comes even remotely close to it's potential specification. Of course, no one has any devices built to utilize it yet but like May flower follow April showers, they will s(h)urely come.

Regarding current bus formats......what Hawk and Boswell said.

"That said, there is a good reason why most multi-channel interfaces are FireWire and not USB. FireWire is a peer-to-peer protocol and can stream reliably from interface to disk at rates higher than a host-client protocol like USB."

I like the way you talk Boswell.

Usb is for mice and computer peripherals.
Firewire is the Standard that hasn't been set yet ;) And as long as usb can be disrupted by some other usb device, it is unreliable in a audio related computer environment often plagued with unreliability.

UsersShouldn'tBuy,

Brien