I am using two D740X, 80 gigs in a raid configuration for about 2 months now. Have not had any problems. They make a different sound then the WD's when they search, but I cannot really even hear them over my chasis fan, they are very quiet. I would recomend them, but I would refer to John's post earilier, "...Maxtor gives you a choice when buying the D740X. The PN has an L instead of a J." Make sure that the Part Number has an "L" in it and not the "J" or you will not be getting the Fluid Bearing... The ones with the fluid bearings are assembled in Japan. I got mine from New Egg, the Fluid bearings are not always listed under the description, so be ware.
Although, that 8m cache would be suite. 😀