[USB]
For ME, it makes easy interfacing, trivial!
And it makes difficult interfacing, impossible.
Certainly looks that way. If you have a USB device, the drives for it
for the OS you're running, etc then it all (normally) works. But that
applies to just about any interface. And if you want to use an USB
product on an different machine or OS for which there aren't drivers, it
seems to be a lot more difficult than, say, using an RS232 or HPIB device
on a differnet machine.
-tony