Shuffle's data transfer rate & USB
While 36Mbps is a lot less than USB 2.0's theoretical max of 480Mbps... Nothing I've ever seen even comes close to 480Mbps.
It's the whole theoretical vs actual... The same sort of thing happens in Ethernet and probably lots of other things... On a good day, with all the right conditions, maybe you get 60% or 70% of Max.
So considering that the same is true for USB 1.1 ... 36Mbps transfer rates is a very significant improvement... And while it's not up to around the ~256Mbps (or so) Max USB 2.0 transfer rates seen in tests like:
Even a lot of those tests, the numbers for certain conditions fall significantly short... 36Mbps isn't great... but it's not all that bad. ;)