I have a mediator it is not as fast as the g-rex but the drivers are better and its bug free. and mediators are better supported.
Also in terms of IDE interfaces which is the best solution for speed
that would be the FAST ATAmkIII (POWERFLYER) i have one, only problem with it is that it eats my cpu.but it is the fastest ypu can get on yhe a1200
adonay :-D