Perhaps some of the cheaper ones cause problems, but most do not. I've used many, even in production systems, without any problems. Many / most will even go to 80 MB/sec mode (tested with an SSD). I've used them with all sorts of machines - AlphaServers, Quadras (on both IDE and SCSI with SCSI-IDE adapters), PowerMacs (again, both IDE and SCSI) and so on.