Our experiences to date with the Western Digital WD740ADFD have been terrific. The recent updates to the drive have brought it into the same performance sector as the larger WD1500ADFD drive. We found the overall write performance and sustained transfer rates to be excellent and class leading in our test results. The drive even has improved thermal and acoustic characteristics over the other Raptors, although it's certainly not competitive with other drives. Of course those drives do not have to contend with 10,000 RPM spindle speeds and firmware that is generally designed to extract the greatest amount of performance.
The WD740ADFD is not without faults. The obvious issue for most users is the capacity of the drive. Considering the rampant increase in storage requirements for games, operating systems, and video/audio needs, 74GB can start feeling cramped in a hurry. The other issue is price. The drive is currently selling for around $140 with rebate where the WD1500ADFD with twice the capacity can be had for $190 with rebate. In these terms, the 150GB Raptor is a much better buy. Even then, you are paying a large premium for performance, though the performance improvement is noticeable in both objective and subjective terms.
While the platter sizes have changed on the new 74GB Raptors, for the most part the story remains the same. The Western Digital Raptor drives still offer some of the best performance available (outside of SCSI and SAS). The high level of performance is somewhat offset by increased noise levels and operating temperatures, as well as the already noted higher prices and reduced capacities. In an ideal world, we would like to see some of the new 160GB platters used with a 10,000 RPM spindle speed, but there are technological hurdles involved with getting the drive heads to read and write data that fast. We expect to start seeing SCSI and SAS drives in the future that have platter sizes above 74GB, so hopefully Western Digital will be able to follow suit with newer Raptor models sporting higher areal densities and the accompanying increased capacities. Looking at the performance improvement Western Digital garnered by moving from a 37GB to a 74GB platter size in our benchmarks here, we can only dream about what we might see with 150GB platters.
We still have difficulty with recommending these drives to most people when excellent performing 500GB drives can be had for around $150 now, not to mention the well balanced smaller capacity models like the Seagate 320GB 7200.10 drive for $90. Many users will be hard-pressed to even notice the difference between most of the modern hard drives currently on the market. However, we are enthusiasts at heart, so in situations where money isn't a concern we would have a WD1500ADFD as the boot/OS drive with our favorite games installed on it, and we'd pair that with a top performing secondary 320GB~750GB drive for storage and other applications. Of course, if you are into benchmarking or have a specific application that benefits from it, then a pair of Raptors in RAID 0 will be even better. In the end, if you want one of the best performing drives in the market then you cannot go wrong with the 74GB or 150GB Raptor drives.