@SHADES:
*does some editing too*
The classic Amigas that features an IDE-interface (A600, A1200 and A4000) does as you say not utilize anything else than PIO-modes. Not strange as they are constructions from the ATA-1 era and are made to be highly cpu-driven. This gives slow speeds and a high cpu-load, but it has given a lot of flexibility allowing support for 4-device-hacks, large harddrives to be added afterwards.
Wether the harddrive-controller uses DMA to access the computers memory has nothing to do with if the harddrive-controller access the harddrive using an UltraDMA-mode. You could have a harddrive-controller accessing the computers memory using DMA, but still only accessing the harddrive with PIO-mode 0. Ofcourse the opposite is also possible - a harddrive-controller not being able of doing DMA, instead needing the cpu to transfer data to the computers memory but still accessing the harddrive using an UltraDMA-mode.
See the harddrive-controller as a bridge between the harddrive and the bus the harddrive-controller is connected to the computer via.
/Patrik