The Subway is USB 2.0, not 1.1, but the speed is limited by the A1200's Clockport. So they're totally usable for USB pendrives, mice, keyboards, scanners, printers, card readers, guitars, rocket launchers, humping dogs and all those other USB gadgets we couldn't live without.
But as gertsy said, if you just need it for storage and swapping files between an Amiga and a PC it's best to use a PCMCIA SD or CF card reader, which is cheaper and much faster.