...HID devices are "low-speed" USB devices and won't benefit from 2.0 at all (at least in a practical sense.)
-Most- HID devices are low speed, 1.5Mb/s. The specs allow for full speed, 12Mb/s, and there are advantages for devices such as arcade keyboard encoders with lots of buttons. High speed USB 2.0 isn't much use for HID.
Ok, let me re-phrase that.
While the spec allows for "full speed" HID devices, I have never seen one in my travels. My HID devices and the current lot of similar HID devices from other vendors are also "low speed" devices. Added to that, given the penchant of commercial controller manufacturers to save money when producing items like joysticks, mice, keyboards, etc and the fact that "full speed" controllers are more expensive than their low-speed counterparts, not to mention that OS support is limited to non-existent without special drivers for anything else, make it likely that things will be that way for a while to come.
And since the 1.1 spec handles everything but "high speed" devices anyway, 1.1 is the way to go for your HID controls to avoid any potential difficulties.
RandyT