SCSI is quite complicated and not infrequently difficult to set up correctly. Parallel port connections are slower than the other two alternatives. Finally, the digital interface known as Firewire promises superb integration and communication with other digital components such as digital camcorders and will permit perfect copying of digital material. The perfect computer will include all of these interfaces. Eventually, this technology will become more reasonably priced and such products are obviously very desirable as they take up much less desktop space.
Speed is no longer quite as critical.
The 300's do make a marked difference in many graphics programs, but not as much as one might have expected. Graphic users will always want more speed, but the difference between a 300 and a 400 are not substantial. A 1000-megahertz chip will be considerably faster, but not truly awesome. A Ferrari perhaps, but one that will not get through New York City traffic, or the bloated software programs, all that much faster. Laptops, of course, are a different matter.