Hi,
I've been using various SATA-IDE adapters for ages. There's no slowdown and in most instances where the IDE machine can handle the faster drive, SATA via an adapter has been noticeably faster than the fastest IDE drives I have.
IDE SSDs are not hard to find:
http://eshop.macsales.com/shop/SSD/OWC/Mercury_Legacy_ProOn my A1200, I boot from an IDE attached CF card (which isn't quick; Amiga IDE, not the CF card, is pretty slow) and use a SATA drive attached to a SATA-IDE adapter which is then connected to a IDE-SCSI adapter which is connected to the Blizzard 1260 SCSI card, which is 10 megabytes a second. In AmigaDOS, I typically got 7 to 8 MB (big B) a second transferring large files over the Blizzard SCSI.
On my A4000, I can boot from the CyberStorm PPC SCSI (40 MB/sec), but hardly ever see more than 10 MB/sec in normal use. What makes all the difference for both the Blizzard SCSI and the CyberStorm SCSI is the DMA - you can clearly tell the difference between transferring on IDE (which slows everything down) and transferring on SCSI (which barely affects other programs).
Bottom line - a slow drive on DMA SCSI is MUCH faster, overall, than a fast drive on IDE.
