This isn't true. Linux doesn't allocate more bandwidth to devices than Windows. It follows the same bandwidth allocation rules (e.g. 10% of bandwidth is reserved for control transfers). If anything the USB stack and drivers are just faster and more efficient.

Here's a video the same demo with a USB 2.0 drive under EHCI. Linux shows 35MBps. Granted, I do need to run with some standard benchmark tools. ;)

Actually, USB 3.0 was targeted for mass storage devices. They added the concept of Bulk Streams to support "out-of-order data transfers required for mass storage device command queuing." (USB 3.0 spec, section 4.4.6.4) Basically, the host can queue up to 65K SCSI commands, and the device can choose which command it wants to service first.

The host doesn't have to poll the device to see when commands are done because they added device notifications to USB 3.0. So the host fires off 65K of SCSI requests and the device asynchronously notifies the host as they get done. I'm no firewire expert, so I have no idea if it does something comparable. :)

Yes, USB 3.0 is still quantized. However, USB 2.0 devices can be sampled more often than 1ms. The 1ms frame was broken into 8 microframes in USB 2.0. I'm not a sound engineer, but it seems like you could have some buffering on the device side to send several sound samples with time stamps in one microframe. The software on the other side could re-space out the samples. Would you really notice a 125 us delay when playing music?