All memory cards have on-board controllers, except xD (and the old SmartMedia cards), so that's really not any different. CF has the highest speed transfers by far and that's a BIG difference. CF cards do NOT have a lock switch, and do not support on-board DRM, as many others (MMC,SD) do, which makes the licensing a little cheaper too. The reason CF cards are so much faster. and bigger physically, is that they use what is basically a mini-ATA interface (just like a hard drive). The downside is the size of the connector - but future CF cards will switch from Parallel-ATA to Serial-ATA, making for even faster transfers and much smaller connectors.
dmz